Second-hand Rocks and Prosperity Pricing

A long time ago, I remember reading a book which described sedimentary rocks as a kind of “second-hand” rock because they are formed from other materials – such as, from the remains of previously living organisms, or from fragments of other older rocks. But yesterday, I encountered some literal second-hand rocks!…

Whilst returning back to town from FOSSASIA 2016, I passed a familiar second-hand store that I used to go to whenever I was in Jurong East. CASH CONVERTERS! – that good ol brick-and-mortar franchise in the business of “buying and selling unwanted goods” – land of excess factory stock, used CDs and other outmoded forms of media entertainment, joblots of made-for-tv egg cooking devices, tennis racquets tanned yellow with age, furry massage mats, porcelain dogs, used mugs, extruded plastic god-of-fortune statuettes, bowling balls wrapped in cellophane…



Speaking of hard objects enthusiastically wrapped in plastic, I came across a section that I hadn’t quite noticed in previous visits. Lodged in a rather small shelf, in a few red plastic baskets (not dissimilar to the green plastic baskets I used for sorting my rocks in the past), I discovered that someone had secreted a whole cachet of rocks. Yes my friends. In the middle of Jurong East’s Cash Converters is an entire SECOND HAND ROCK SECTION. (Maybe I should start my own rock shop like them too huh)






No provenance. No information. Just rocks wrapped so tightly in plastic that in some cases you couldn’t see them properly. Which makes it slightly alarming when a few of them are not in protective plastic shells (I worry for a moment, is the sweat on my grubby hands in danger of inflicting corrosion upon these rocks??)

And of course, because Cash Converters has made the re-selling of seemingly unwanted and useless objects their entire business, there is also a price tag.




How does Cash Converters determine the price for rocks? From looking online, people say that Cash Converters in other places use the prices of other existing online catalogues such as ebay, argos, etc to determine an object’s value (when it was new) and then quotes a fraction of that (pricing it so that CC would eventually still make a significant 60-100% profit on the sale of the object).

But… rocks? Even as ornamental fengshui rocks? Is there a special catalogue for fengshui rocks here? How does the CC staff evaluate it? Is it size, weight, appearance?

Also, seriously, what is up with the prices all being XX.80 or with the number 8 in them? Is the inclusion of 8 in the pricing a strategic tactic for pricing within chinese markets?



What is fascinating is that when you look at the centrepiece display within the interior of second-hand shops like Cash Converters in Singapore and the glass front of the second hand shop, it is often dominated by highly valued prosperity symbols and objects of religious syncretism, mixed up with the visual language of designed lifestyle objects, on a bed of laser-cut acrylic and LEDs.


I also hasten to add that whilst I was at Cash Converters, no less than 4 middle-aged Chinese men shuffled through this aisle and spent a long time carefully evaluating the rocks on this shelf, so I personally I did get the impression that these rocks were definitely an object of curiosity, and perhaps by extension, even objects of desire…

Prosperity Pricing? The use of number “8” in prices of Chinese consumer products

Some googling takes me to this paper: The Use of ‘Lucky’ Numbers in the Pricing of Chinese A-Share Initial Public Offerings where the abstract notes that existing marketing literature shows that “the number 8 is consistently used as a price-ending in advertising for Chinese consumer products” – to capitalise on investor sentiment.

Tumbling down the Bismuth Steps

So the other day I went to see Interstellar, which was fairly enjoyable if not for the massive plot holes and inconsistencies and its unnecessarily long running time. If there was one thing I appreciated about Interstellar, it was that at least they attempted to visualise the 5th dimension. Even if it ended up looking a lot like a giant building-sized piece of bismuth built out of shonky wooden library shelves, tracing paper, and a lot of black thread. At least they tried. I’d like to see more people try to imagine what it might look like, even if the representations fall flat on their faces.

Bismuth Structural Rainbow
Bismuth from Flickr user cobalt123

The structural qualities of minerals is fascinating. On a personal level, I am attracted to rocks and geological features which are so orderly and angular that one imagines – that if the image were presented out of context – then one might just believe that it could be man-made, although in reality these shapes and forms are a product of nature. Like a artificial/man-made mine, in which square chunks are methodically hewn out, or dug out to form huge man-sized hollow hopper crystal structures in which humans could nestle within… To think of planets as petri dishes for life with their respective larder list of minerals and baking temperatures!…


Here for example, this is the Pool of Serpents (Poll na bpeist) – a naturally formed olympic sized pool cut-out in the rocks of the Aran Islands, which I went to see last year. My wish list of places to visit in the coming spring includes Fingal’s Cave on Staffa (Inner Hebrides, Scotland) with its hexagonally jointed basalt columns and the Delabole Quarry in Cornwall with its crazy steps of slate.

minerals 2
Naturally formed hexagonal Bismuth illustrated in my mineral book

The distinctive hollow stair-step crystals of the Bismuth are mainly the product of artificial processes – you can grow hopper crystals like these at home. The metallic iridescence comes from a thin layer of bismuth oxide causing light scattering.

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Who doesn’t like shiny things? In my own digital paintings, I found that painting in some “shine” with pin-points of white light (like a 3D model) give an image a realism/fakeness to them. I would make latex clothing if I had the resources to or if I were more inclined to doing something fashion related (as it were, I do intentionally avoid having to think too hard about clothing as I think time can be better spent on other things). But I enjoy looking at glossy and shiny materials, and I don’t understand why it has an image of being “kinky”.

Perhaps I was born in the wrong time, and I think a skin-like rubber material like latex has an interesting shine to it and as a material for clothing it is more representative of the times. The question of how latex became kinky is something I shall have to look into further some other time, but to go on with the story…

So this morning I continued experimenting with Meshmixer. I had drawn an imperfect klein surface and was hoping to figure out how to edit its shaders to make it less or more “shiny”.

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(I do apologise for this poor approximation of a klein surface – with a red “rubber” shader)

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Next, I dropped in a jpg of the Witch Head Nebula which I had cut down in size into a “shader”. This was the somewhat unexpected output…

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I realised… that’s not just the shader. That’s the shader… and the wikipedia page it came from!

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Wikipedia browser window underneath Meshmixer window

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Looking more closely, I realised it was not only the image of the nebula; it was also reflecting other things I had recently accessed on my computer – there was my personal wiki on another browser window and some processing code I was looking at in a text editor! There were also glimpses of a generative snowflake I was coding up in openSCAD, turned blue instead of yellow.

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Congratulations to my mac and meshmixer for producing its own imaginative rendering of the 5th dimension before I could do so myself. I guess I’ll have to catch up with it by producing my own visualisations…

The Rocks of Inis Mor

TEAM FIRE visited Inis Mor the other day. I asked to be taken to see the following: (1) a castle (2) an irish pub (3) a cliff by the sea (4) ROCKS; the first three were easy to find and on the last item, George exceeded himself by deciding to take us to Galway and then to THE ARAN ISLANDS! Galway on its own deserves a whole post to itself but the Aran Islands was completely unreal. Picturesque, completely isolated, harsh weather and extremely beautiful terrain, the island of Inis Mor was apparently the model for Father Ted’s Craggy Island, and also the star of the documentary Man of Aran. We were to stay at a cottage that had been built for the filming of this fictional documentary about life on the islands, which had apparently represented a kind of traditional rural irish lifestyle, now lost in time…

To begin, the ferry ride was already something out of a storybook. One unaccustomed to the seas might be compelled to write home immediately after experiencing the life-changing highs and lows of the ferry from Rossaveal to Inis Mor. Seemingly death-defying, stomach-churning multi-storey heaves and drops over ridiculously high rolling waves of the Atlantic, at some points actually eliciting involuntary high-pitched screams from tourists onboard, clutching the armrests of their seats with white knuckles. With each roll, the horizon would completely disappear and reappear from view. We had already taken the largest ferry, a 400 seater, as we were told that the smaller ferries would not sail on days with poor weather. Indeed I’d imagine a smaller boat being easily swallowed by the waves. Having sat on a fair number of boats in my time but only in the relatively sheltered waters of Singapore, this kind of extreme sea-crossing was something I had never witnessed before.

After some confusion and having to call for help to get a taxi after we wandered away from the pier (into what we realised was a completely sleepy town) – we were eventually received with much hospitality at the Man of Aran Cottage by Joe and Moira. We read that the cottage had been built for the documentary “Man of Aran”, hence its moniker. It is curious to think that it was probably built with the intentions of making it seem as authentic as possible, but now some 80 years on this house seemed as ancient as the others, perched on this unlikely point of the island.

The cottage is situated a fair distance from the “main town” area and this also meant there was absolutely nothing around us at night. The nearest shop (a SPAR, which closes at 6pm) and pub (Joe Watty’s) are close to the port, whereas the Man of Aran is located at the centre of the island, close to the fort. But in the morning, the view from the Man of Aran Cottage is fantastically spectacular. You know like when you hear the frightfully loud sound of a heavy wind whistling on the window when you sit in your city flats and pretend you’re far out in the wilderness? WELL PRETEND NO MORE! This is the real thing.

We were fortunate to have met Andrew at the Man of Aran Cottage; another guest at the Man of Aran at the time. He had spent almost a year on the island back in the 60s, and had penned a book about his experiences in a book, “An Aran Keening”. (We later went down to the bookstores in Galway and tried to find it). He was very kind to show us the way to the Pool na Bpeist or Pool of Serpents, and as we walked there I realised it was very very fortunate that he brought us there the way he did, for we would never have found it otherwise, and the approach he took was very much better.

For the most part, it is simply covered in this endless face of rock, cracking at the surface. Most of the rock is patterned in bold grykes. The rock itself is similar to that of the limestone at the Burren across the ocean; Burren from “Boireann” which means “a rocky place”.



Glacial Erratics
Glacial erratics are rocks which do not belong to the rest of the rock below it and is thought to have been deposited on top of the surface when they were carried on a giant iceberg that floated over the rest of this island during the ice age. Then when the ice melted these large odd stones were deposited on top.

Another glacial erratic


Green moss on Glacial erratic







The plants that lived in the environment were also incredible. You would see these lovely little plants everywhere, growing between the cracks in this almost inhospitable environment and they would look so downy and soft and inviting but if you ever tried to peel one off you would discover they were ROCK SOLID. Tough as nails! Impenetrable! Unchewable! Teeth-breaking! Not to say I tried to chew them but attempting to dislodge a tiny corner of it was more like trying to chew on a car tire.







We were buffeted by strong gusts of wind, fit to blow a person off the cliff face, so we were sometimes crawling slowly towards the edge; creeping over the wet rocks of Aran, over an endless maze of low stone walls, endless landscape of nothing but craggy rock.


This is the Pool of Serpents (Poll na bpeist), a naturally formed geological feature which looks like a rectangular olympic sized swimming pool. Although this is not evident in the picture, as the winds were high (and we so unaccustomed to walking on wet rocks) we were terrified walking so close to the edge…




Dun Aonghasa can be seen at the top of this cliff. It is the one of the most important prehistoric forts on the island and a UNESCO world heritage site. It is basically a very very old fort that is thought to have been used since 1100 BCE.

We also discovered that an entrance fee was actually being charged for people entering Dun Aonghasa, but the point at which they charged travellers was down below. But because we had come from a more ‘extreme’ walk along the rocks and strong winds and then climbed over a low rock fence to get into a well-worn path covered with many tourists in hiking gear, we slipped through without passing that checkpoint. I find that it is a very curious thing to fence up all the rocks and set opening and closing times – we saw the same thing being practiced at Stonehenge. It is baffling because I think me and George operate more along the lines of the “let’s walk in this direction until we find the rock” sort of manner, without care of the “opening or closing time of the tourist attraction”. The rocks on this touristic path were rubbed smooth and very hard to walk on, unlike the rough rocks of the rest of the island.


Dun Aonghasa



The view from Dun Aonghasa

Finally I wanted to add that we found a large rock that had been intentionally placed on the road to stop cars from driving down it as it is used by children frequently. Not a glacial erratic, but I love how it has been placed there with a purpose, on a road. How lovely, to imagine a place where they put a rock to block up the road so that cars won’t drive up and down it, so that people can walk on it freely!

I’ll stop here for now but… NEXT UP: The plants and wildlife of Inis Mor!

Comparing English Slate and Murai Slate from Singapore


These are pieces of slate recovered from Pulau Saigon. Slate is a metamorphic rock that is composed of clay minerals that have been put under great pressure, causing fine grains of clay flakes to regrow in planes perpendicular to the compression (due to the mica in the rock). As a result it will be hard enough to “clink” when hit with a hammer, and also have a distinctive layered appearance or “foliation”.



These slates are known to be slate of UK origin, brought over on a ship from the UK to Singapore to be used as a building material for (colonial) houses here. The slate may also have been used as ballast. I was unable to find a chart or guide to identifying slates, as they are technically named after the region they came from. To the untrained eye, I guess they look like the traditional grey tones of slate from Wales.

I looked for more general information about slate produced in the UK for construction, and found various information and pdf guides on the English Heritage (Officially known as the “Historic Buildings and Monuments Commission for England”):

“Stone slates were mined at Purbeck in Dorset, at Collyweston and Duston in Northamptonshire, at Stonesfield and elsewhere in the Cotswolds, in Yorkshire and occasionally in Derbyshire… At Collyweston and Stonesfield, the splitting was carried out by frost action. The raw block was either stored underground or taken to the surface where it was wetted and covered in earth until the frosts came. The frost then swelled the natural moisture within the stone and split it into slates. Frostsplit slates may be thinner and therefore lighter than those split by hand.”

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Sidenote: When I look at this, I think all this sort of stone collecting and stone arranging must be how the romans invented crazy paving. You know, CRAZY PAVING? All broken up into all sorts of interesting shapes? (Unfortunately this joke won’t be quite as funny to the majority of Singaporeans who don’t get to do any of their own paving ever, owing to the fact that most people don’t have landed properties to pave…)

In comparison, this is what Murai slate/schist from Singapore looks like.

murai Schist
I noticed these specimens at the Raffles Biodiversity Museum were casually labelled “Murai slate”. But a geology enthuisiast in Singapore would have more commonly read about the “Murai Schist” (part of Jurong Formation) in reports about Singapore’s geology. But this does look like slate because the characteristic of schist is that its mineral grains should be visible to the naked eye. And I don’t see any conspicuous large grains of mica flakes here, so I am inclined to think this would be defined as slate.

In any case, the two types of rocks – slate and schist – can be observed to have other similar properties – apparently the Schist is metamorphosed more than the Slate, so they are very similar, except that the Schist is even harder, and the equivalent of cleavage or what we would call “slaty cleavage” is known as “schistosity”.

Also, from the report “Geology of Singapore” (Published by DSTA):

“It is not proposed that the Murai Schist be recognised as a formal geological unit, but rather as a zone of well-developed cleavage in rocks otherwise recognised as sediments of the Queenstown, Jong ,and Tengah Facies. The Schist zone forms a belt up to 0.5 km wide in Ama keng, trending northeast from Tanjong Skopek to include the area originally described by Alexander (1950). A small schist zone was found on the north arm of the Pasir Laba Ridge (GR 295494) and another zone, not recorded on the map, was found in the Jong Facies in Jurong (GR332452).”

So I guess the brown rock above might actually be Slate from the Murai Schist. Who comes up with all these terms anyway?

Videos of the Pulau Saigon Slate:

Slate (Top view)

Slate (Side view)

See also:
The Collectors of Pulau Saigon: Murex Trapa shells, and Pyrites (Fool’s Gold)
The Chert of Pulau Saigon, a former island in the Singapore River
Bone, Metal, Wood, and Other Artefacts found on Pulau Saigon

The Chert of Pulau Saigon, a former island in the Singapore River

I must confess that I had not thought much about the chert of Southeast Asia until now. Is there a lot of chert in Southeast Asia? I don’t really know firsthand. Most of the accessible beaches of Singapore are artificial and made of recent sand depositions from other places, and there are no points at which I can simply casually wade in and around the gravel of the Singapore River – much unlike the Thames in London, which has many wide banks upon which one can wander about without disturbance. I have, on past occasions, observed the proliferation of chert in the River Thames, and also, the endless amounts of chert/flint on Lyme Bay. So, what sort of rock is to be found in the rivers of Southeast Asia then?

Chert/Flint with cute echinoid in Natural History Museum, London


Chert/Flint on River Thames (London, 2012)


Chert/Flint on Lyme Bay (Jurassic Coast, 2012)
To be honest, to this day I still feel that my definition of “chert” is a bit fuzzy, despite having several encounters with chert and having read up on chert before. I do know at very least that Chert is formed by the recrystallization of siliceous skeletons of marine animals into microcrystalline sedimentary rock. From what I have read so far on it, I’m going to just take it to be a more inclusive term for most of the microcrystalline quartz or silica. And as from what I saw and read at the Natural History Museum in London, flint refers to the chert commonly found in chalk or limestone…

From Wikipedia: “There is much confusion concerning the exact meanings and differences among the terms “chert”, “chalcedony” and “flint” (as well as their numerous varieties). In petrology the term “chert” is used to refer generally to all rocks composed primarily of microcrystalline, cryptocrystalline and microfibrous quartz. The term does not include quartzite. Chalcedony is a microfibrous (microcrystaline with a fibrous structure) variety of quartz.

Strictly speaking, the term “flint” is reserved for varieties of chert which occur in chalk and marly limestone formations. Among non-geologists (in particular among archaeologists), the distinction between “flint” and “chert” is often one of quality – chert being lower quality than flint. This usage of the terminology is prevalent in America and is likely caused by early immigrants who imported the terms from England where most true flint (that found in chalk formations) was indeed of better quality than “common chert” (from limestone formations).

Among petrologists, chalcedony is sometimes considered separately from chert due to its fibrous structure. Since many cherts contain both microcrystaline and microfibrous quartz, it is sometimes difficult to classify a rock as completely chalcedony, thus its general inclusion as a variety of chert.”

I am fed up with local people having the name “Chert”, thus foiling my attempts to investigate whether Chert rock naturally occurs in this region. Anyway, the reason why I am wondering whether there is a lot of chert in the Singapore River is because of this chert specimen in the Singapore River. Knowing that some of the slate comes from the UK, I realised I had never seen THE CHERT OF SINGAPORE in person before, although I have many Chert specimens from the UK, so I wondered if this chert rock had actually come from elsewhere….


Chert rescued from Pulau Saigon, a former island in the Singapore River
How do we tell this is “chert”? Largely because of its “waxy luster” and conchoidal fractures, which produce a sharp edge. Brittle materials such as chert have this quality, allowing it to be shaped into knives and tools.


Conchoidal fractures



Waxy Luster
Today I was very fortunate to be able to spend a few hours at the Archaeology Lab at NUS, where I attempted to do a preliminary photoshoot of certain artefacts from Pulau Saigon, and began running some shots through Autodesk’s 123d Catch in order to produce 3d models of some of the objects. Thank you to John Miksic and Goh Geok Yian for letting me occupy their pantry for the entire day and sharing with me about their work. It will take me some time to process all the information captured today, but you can expect more posts on the topic in coming weeks… (They always need more committed and responsible volunteers at their lab to help them sift through, sort through, and wash material, so if you’re interested in archaeology in Singapore and are available to volunteer your time on Fridays between 10-5pm, leave me a note and I will pass your contact on to them.)

Pulau Saigon (PSG) Stone and Rocks






14th C Stoneware


European Porcelain

Oh and another strange thing that happened is that I encountered the word “Diatomaceous” twice within one hour today. Whilst reading the comments to an instructable about building a solar food dryer to find out if others were worried about insects getting into their solar food dryer, I discovered a comment suggesting that “Diatomaceous earth” be scattered because its tiny, light yet highly abrasive nature makes it suitable as a mechanical insecticide, making it unpleasant for tiny ants to walk upon – basically getting inbetween their tiny exoskeleton joints and absorbing lipids from the waxy outer layer of insects’ exoskeletons, causing them to dehydrate from the inside out rather quickly, leading to the death of the insects. A few minutes later I read that chert occurs in diatomaceous deposits and that kind of chert is known as diatomaceous chert. The word diatomaceous refers to diatoms, which consist of tiny microscopic marine phytoplankton, along with their fossils…

Which brings me to…. MICROPALEONTOLOGY, and the study of microfossils! Anything that you can study with the naked eye is probably considered a macrofossil. Micropaleontology is surely a field of study that is after my heart. A micropaleontologist might typically be a specialists in one or more taxonomic groups because it is something that requires so much specialisation to study the fossils of tiny tiny creatures. Speaking of tiny things, this reminds me of micrometeorites. And subsequently… astrogeology. I think this week if you asked me what is my dream job might be, it might be to study to become a micropaleontologist or an astrogeologist. Yeah, I can dream, can’t I?

See also:

The Mineral collection at the Natural History Museum, and Flint Nodules along the River Thames
Bone, Metal, Wood, and Other Artefacts found on Pulau Saigon
Made-up Road Names and Temporary Islands
Ruins in Reverse

Secret Compartment Rocks

Speaking of rocks, I saw some rather interesting rocks in Pompei. Obviously, we went to see a lot of rocks in Italy, especially what with all these ruins and archaeological sites. But sometimes what you need is just a little rock camouflage.

Soundbox Rock (at Il Principe, a restaurant in Pompei)

spy rock

Powerplug Rock (at Pompei Scavi)
Yeah, I am thinking I should investigate further on how to hide things inside rocks or make secret compartments inside rocks…

See also:

Bone, Metal, Wood, and Other Artefacts found on Pulau Saigon

A photo of a photo of a torn map of Kampong Saigon…
Last year whilst at the library, I copied out a list from Jennifer Barry’s “Pulau Saigon : a post-eighteenth century archaeological assemblage recovered from a former island in the Singapore River”. I completely forgot about this document but just unearthed it today, so I thought I should put it online in case anyone should be interested in the “OTHER ARTEFACTS” list found in this little catelogue of artefacts, including a detailed list of ceramics finds, and flora and fauna. As the ceramics and flora/fauna lists are very very long and detailed, I will leave it up to those who are interested to locate the book at the National Library of Singapore (Lee Kong Chien Reference Library, English 959.57 BAR) and read those portions for themselves.

I wanted to purchase or request for a copy of this book but it seems impossible to track down the publisher, Rheidol Press, and they either have ceased to exist or do not have any sort of online presence at all. No copyright infringement intended here by reproducing part of the text here, but it seems impossible to even find or contact them to even ask for the permission. Short of writing to their postal address in Stamford (which conceivably could have changed by now), there are no other leads or clues or ways to contact them (although I suppose I will try to write to them to see what happens). I have never even been to Lincolnshire nor have I ever thought of going there, and I find the idea of an obscure book about Singapore’s own little-known Pulau Saigon being published there very strange indeed.

I have retained all the author’s original typos in the following copy of the list – this is exactly as it was on the page.

From Jennifer Barry’s “Pulau Saigon : a post-eighteenth century archaeological assemblage recovered from a former island in the Singapore River”


Archaeological finds began to appear at Pulau Saigon in 1988 when bulldozers first moved in to start work on the Central Expressway tunnel. Tan family members who owned the petrol kiosk on the island brought this to the attention of Mr Koh Lian What who in turn alerted authorities at the National Museum and the National University. A prompt rescue operation was organized and a team of expert, including Dr C. G. Kwa, Mr Lee Chor Lin, Dr J. Miksic and Mr Koh, was permitted to collect finds and soil samples. Collections were made between November 1988 and March 1980 but no systematic archaeological excavation could be undertaken due to constraints of time.


Broadly speaking the site covers the 170 years from the early 19th to the late 20th century, the period between the arrival of Sir Stamford Raffles in 1819 and the initial construction in 1988 of the tunnel at Clemenceau Bridge. The bulk of ceramic finds are generally consistent with this time frame, up to about the mid 1960s, although there are a few sherds which pre-date the 19th century.

Apart from ceramic, which accounts for the greater part of the entire assemblage, finds include artifacts of glass, bone, metal, wood, stone, plastic and rubber as well as faunal and floral remains. These include a large group of marine shells identified by Mrs Emily Glover of the Natural History Museum, London. There are eleven species of gastropods and give of shallow water burrowing bivalves, two of which are often found in mangroves. All are common to the Singapore area and many are widespread in the Indo-Pacific. Glover notes that the small holes in many of the examples were drilled by predatory mullscs and not by humans, confirming Koh’s view that there was no prehistoric habitation of the site. This possibility had been proposed during the early stages of the rescue.

(…) Before 1889 one would expect that, generally, the deeper finds would be the oldest; yet some of the more recent finds are below 2 and 3 meters of mud, such as the coins dated 1926 and 1883 respectively. A late 19th or early 20th century Doulton square-mouthed stoneware bottle was found at 2m depth. This clearly indicates massive disturbances which, no doubt, had been caused by the dredging of the river, and the subsequent use of this archaeologically rich material as landfill.



Asbestos: 2
 6 small (3 red, 2 blue, 1 yellow, in film roll container)
 40 approx. (in plastic bag)
 1 bone or ivory with black bristles
 1 bone or ivory toothbrush with white bristles
 2 bone or ivory toothbrush handles
 1 carved tortoishell? handle
 1 wood bristle base
 1 wood handle
Corks: 3
Electrical fittings:
 3 white ceramic
 1 bulb filament
 1 small glass bulb
 1 small battery
 1 belt hook (s or snakes-head shape)
 1 bolt
 1 brass lid
 1 buckle
 1 button
 1 cigarette holder
 8 copper coins (Straits Settlement 1884, 1887, 1894)
 2 coins (1 round, 1 square)
 1 door furniture?
 1 fish hook
 1 lamp base? (corroded)
 4 lead pieces plus ore workings
 7 nails plus fragments
 1 pin
 1 scale hands?
 1 wall hook
 1 spoon (European type)
 1 bakelite threaded neck
 2 pink fragments
 1 political party badge
 1 spoon (Chinese type)
 1 table tennis ball
 2 (degraded)
 1 cylindrical pounder
 8 white marble spheres plus one hemisphere
 2 dice (marble, limestone?)
 3 small (modern compound type)
 1 iron spike or pick, wood shaft
 1 iron bill-hook, wood shaft
 1 carved comb (fragile)
 1 broom or brush handle
 1 oar or paddle
 1 clog or shoe sole


Coal: 1
3 flints
1 flint knife? (previously labelled as such)
8 flint tools?
1 pyrite (also known as Fool’s Gold)
1 green stone
1 piece of lava or pumice
24 slate plus 3 knives (previously labelled as such)
35 small smooth pebbles
1 worked stone?
1 quartz (rock crystal)

The Mineral collection at the Natural History Museum, and Flint Nodules along the River Thames




Natural History Museum

Yesterday we went to the Natural History Museum in South Kensington, on recommendation from Hedda, a friend of mine who also collects rocks. We were there largely to see their vast mineral collection and I wanted to see how their rocks were displayed – so we skipped all the animals and went straight for the geological section…


I wanted to be systematic and to read every single label in loving, adoringly attentive detail – but… after the first few hundred rocks and mineral names you begin to lose the will to want to absorb or comprehend it all. There are just too many rocks. So.. many… rocks…….. The sheer volume is almost madness-inducing. And if you will believe the wikipedia entry on the Natural History Museum…

“J.E. Gray (Keeper of Zoology 1840-74) complained of the incidence of mental illness amongst staff: George Shaw threatened to put his foot on any shell not in the 12th edition of Linnaeus’ Systema Naturae; another had removed all the labels and registration numbers fromentomological cases arranged by a rival. The huge collection of conchologist Hugh Cuming was acquired by the museum, and Gray’s own wife had carried the open trays across the courtyard in a gale: all the labels blew away. That collection is said never to have recovered.”

(I haven’t been able to find any copy of Lynn Barber’s “The heyday of natural history, 1820-1870” in order to verify the colourful stories quoted in the entry above but I have to admit I do enjoy the idea of the natural sciences being an attractor for the eccentrics…)

Here is a quick run through the NMH’s collections:



Molybdenite (Grey plates with quartz prisms, from Baker’s Mine, New South Wales, Australia)











lovely mass of dendritic growths


flattened cubo-octahedra


Rhodochrosite massive + tapering prisms


Chalcedony from Iceland (!!!)


Dartmoor Granite (commonly used in london curbstones)


Shap Granite (another commonly used British granite with pink feldspar)




Big lovely Geode


Iridescent massive


Slightly iridescent stalactite


Fantastic radiating bladed crystals


Another iridescent massive


“Iron froth”




Crystal crust


Twin quartz crystal


Interpenetrant twin crystals


“Radiating crystalline in cavities of wad”. Who comes up with these excellent names for the rocks?


Interlacing prisms


Bluish banded massive




Siliceous Sinter in rods and convolutions






Calcite “Iceland Spar”


More Calcite


Even more Calcite


Mamilated Crust with Malachite and Wad


Botryoidal with Crystalline surface


Group of prisms with cerussite




Aurichalcites + Malachites


Prehnite Geode


Removed Specimens











Etc… There were more but near the end I was running through the aisles tearing my hair out whilst screaming “OH GOD, OH GOD, NOT MORE ROCKS”. Also, any one who brings their small child into the geological section – and who is not willing to read every single label to their child – even though their child is shorter than the display cabinets in the museum (and thus unable to see any of the rocks) and then leaves their child free to have a run around the museum like a psychotic howling monkey should be roundly smacked and their child should be taken outside and given a free double expresso. And a free kitten. And a big massive sugary stick of Blackpool Rock. Yeah, I bet that’ll teach them.

Has anyone actually managed to get through all the rocks? Or has everyone else fallen over after suffering the big fat massive rock photo-overload? Great, now I’ll get on with the interesting part of this post…


If there was one useful thing I picked up after going through a few thousand rocks, it was that I have learnt that the type of “Thames River rock” that I have been seeing strewn along the banks of the part of the Thames in London could be identified as “Flint” or “Nodular Chert”.

I have been wondering about what kind of rocks they were for some time but no one could tell me and I did not have a geological dictionary nor the appropriate vocabulary to find what I was looking for. Visually, they are quite distinctive because they consist of a hard, waxy quartz type rock surrounded by a thin layer of something else.

The examples being displayed at NHM looked like this:


‘FLINT’ from the Chalk
Isle of Wight


‘FLINT’ enclosing chalcedony nodule

One might notice that they have chosen to describe it as ‘FLINT’ with the quotation marks around it. Apparently the terms “Flint” and “Chert” are often mixed up or used interchangeably in Britain…

From an information panel at the NHM: “Flint or chert?

The inconsistent use of the terms ‘flint’ and ‘chert’ for siliceous deposits leads to much confusion. However, it is widely understood that flint is a synonym for chert often referring to nodules and bands within the Chalk of Europe. Whereas chert refers to siliceous deposits occurring in other limestones and sandstones.

Flint is formed by the concentration of mobilized silica from siliceous organisms within the carbonate host rock into voids such as burrows and along bedding planes. This process occurs during the early stages of burial. Since the process replaces the host rock, some flint nodules preserve the original features of the Chalk.”


Example of Flint Nodule at NHM

If you ask me, it looks like the Thames Rocks are indeed “flint” nodules then. This is what I observed on the pebbled banks of the Thames in October:




If interested to poke about some rocks, you can find steps access to the River Thames along the south bank – there should be a couple not far from Southbank Centre / Oxo Building / Millennium Bridge.

On the Rights of Rocks to Stay or to Go


Yesterday, a strange incident occurred here in Stamford Hill. It was somewhere after midnight when there was suddenly a loud shattering of glass in the room. No one was hurt, but the whole room was covered in small glass fragments, even in the bookshelves. We had been facing the other wall when it happened. We looked at the lightbulbs to see if they had blown, but in the end discovered the source of all the broken glass was a gaping hole in the window. Somebody or something had broken the window with some projectile. We could not ascertain if it had been a rock or a pellet gun or something more sinister, so we called the police to let them know – just in case it had been a serial incident in the area.


After we had called the police, we discovered a small half-rock on the sofa. By half-rock I mean a rock that looked like it had been shattered into two by a hammer. Unfortunately, as people who have been following my blog or my work will know, I collect rocks (and half-rocks in particular). This is probably the first time that I’ve discovered any downside to being a rock collector, and that would be: Not being sure if the rock on the sofa is the projectile that someone just used to break the window – or just another a rock from your rock collection?…

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Example: Thames River half-rocks from my rock collection

So when Hackney police called back (and came by to file the report), we told them about the rock but with the caveat that that one of us was a rock collector and could not tell for sure if it was our rock or the offending projectile. This did, however, prompt me to take out my bag full of Thames rocks and Paris rocks and I examined all of them. Based on its appearance, it seemed like it could conceivably be one of my rocks… but what would it be doing in the sofa that we frequently dusted off and rearranged? It was a far leap from G’s mantlepiece. And the angle was all wrong for it to have come from the hole in the window…

“You can go ahead and touch the rock,” the policeman said when he came around, “we can’t take fingerprints on rocks or test for minerals or fibers, or that sort of thing.” Good thing to know next time you need to commit a crime with a rock… They ain’t gonna to be able to do much forensics with it after all…

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Later that night, after we had picked up most of the glass off the carpet, I decided to pick up and read The Book of Books which I picked up at dOCUMENTA(13). The book itself is ridiculously huge (23 x 6.1 x 28 cm) and heavy (2.5kg), so I have been deliberating on whether to take the book back to Singapore in my check-in luggage.

Since I can’t take an infinite amount of things in my luggage, I’ve taken the precautions of mailing back parcels of the large and heavy items I had accumulated over the last few months. Recently, I also shipped back a number of very heavy slabs of pavement rocks from Paris – rocks that technically had no value except that they were pavement rocks that I had collected by hand and exhibited in a show. People have been asking me whether I would bring the rocks back to Singapore – and I did think for a very long time about whether I should remove them from their country of origin. But there was no conceivable way that I could leave them there where I had found them, where no one would know their significance to me; how could I ever justify throwing them out? So, I was compelled to take them with me, no matter what. But 20kg of rocks is very expensive to ship from France to Singapore. Firstly, without the help of Elio I would never have been able to even shift them to the post office as they were too heavy for me to carry on my own; and secondly, as it was to be expected, it was enormously expensive to ship them back to Singapore: the resultant shipping for 20kg of rocks cost a few hundred Euros… and on top of that, they are still somewhere lost in transit as we speak… I suppose 20kg of rocks in a cardboard wrapping would look pretty suspicious…


The weight of these items – which prevents them from being physically transported in a convenient or casual fashion – also gives them certain import. For example, after all these travels about Europe, I know for a certainty now that any single piece of luggage exceeding 28kg is physically impossible for me to lift – or so much as feebly drag along the ground, no matter how much I desire it. The truth of the matter is that it is physically impossible for me to lift any piece of luggage that is heavier than 28kg. If I had found a rock that was 28kg heavy, there would be absolutely no question of asking if I would carry the rock home with me because it would not be physically possible to do so in the first place.

I read Carolyn Christov-Bakargiev’s opening essay to The Book of Books with much interest because it involves a story about another abortive attempt to move a very big rock. She writes about one of the few projects that was publicly announced but eventually did not come to fulfillment at dOCUMENTA(13) – the proposal by Argentinian artists Guillermo Faivovich and Nicholas Goldberg to bring El Chaco, the second largest meteorite in the world, from its original resting place north of Argentina, to a temporary location in Kassel that would have been not far from Walter De Maria’s Vertical Earth Kilometre (a metal rod of 5cm diameter that appears as a flat circular disc when viewed from the top but which goes 1km deep into the ground).

Apparently Argentine law prohibits the removal of any of the meteorite fragments from the Chaco province, but had made a turn-around and approved the move of El Chaco specifically for the purposes of documents, with the provincial government citing it as a chance to spread awareness of the impoverished area of Chaco and its meteorites. However, there was opposition to the move from the aboriginal Moqoit natives for whom the El Chaco is a sacred monument, backed by scientists, some of whom have written passionately on the issue.


Image from

As quoted in many articles, one of the most outspoken of letters is from a social anthropologist Alejandro López who wrote: “We firmly believe that this project implies a deeply colonialist attitude, wherein the artists’ desire is to link themselves with the wealth and valuables of the Chaco. Instead of this “transfer” of the meteorite as a sort of “cosmic curiosity,” it would be preferable for those who have the money and prestige to seek to promote the value of the meteorite within its place of origin.”

Searching for other articles on El Chaco, I have to admit that I found it somewhat maddening that most if not all of the news reports follow in the same tone as the letter above, condemning the artists’ intentions as “colonial” or upholding some manner of “deeply colonial attitudes” towards the ways in which “cultural objects” are to be handled.

An AFP report has the headline: “An unlikely alliance between the native Moqoit people and leading Argentine scientists has thwarted plans to ship the world’s second largest meteorite to Germany as a prestigious art exhibit.”

Thwarted! As if the artists were an evil and cruel money-grubbing force trying to steal the rock from the poor poor natives! No doubt, it remains indefensible that the artists failed to consult the Moqoit before submitting the proposal, and that past attempts by colonialists to steal their meteorites (because it was made of metal) have left “serious cultural damage” and left the Moqoit with a legacy of “suspicion and insecurity” towards anyone who should make advances on their rock.

But to chalk every subsequent proposal to move El Chaco down to an act of colonialism is surely just as much subjugating the Moquoi natives and forcing them to keep playing the role of “victim” — trapped within the old colonised-vs-colonialist mindset!

To cry “colonialist” is like falling into the trap of the “anti-colonial” stance; it perpetuates the old narratives of imperialism, colonialism, conquest, oppression, emancipation, etc; it expects that the stories should play out as power struggles between the oppressed and the oppressor; it expects that everyone in the world still has identities fixed by cultural or geographical origins; it expects that artists should make works which then have to be explained from their country of origin or socio-economic background or upbringing. And that is just so… boring.

Carolyn Christov-Bakagiev: “And what if we asked ourselves, beyond this irresolvable contradiction, what it was to see things from the position of the meteorite? It had travelled through vertiginous space before landing on Earth and settling. Would it have wished to go on this further journey? Does it have any rights, and if so, how can they be exercised? Can it asked to be buried again, as some of the Moqoit argue, or would it have enjoyed a short trip to an art exhibition, rather than a science or world’s fair? (…) What is this displaced position, generated by the perception of a simultaneous being in different spaces, where the collapse of time and distance provokes a new sense of what it means to be always in one place, and not in another place?”

Stone Tourism and Geological Accidents

People who have been following this blog or my work for some time might know that I have been getting interested in collecting rocks. Rocks! Stones! Geology! Archaeology! Subjects that are not discussed quite enough in Singapore! But ah, now we are in Paris, where everything is built with stone and rocks! So have you ever wondered, where exactly do the stones in all of Paris’ iconic buildings come from? No? Well, I’m going to tell you more about rocks anyway.

I thought we’d start, for example, with the most famous of famous churches, which would be Saint-Denis, where all of the monarchs of France and their families have been buried from the 10th century until 1789 (with the exception of 3 kings). It stands to reason that such a significant building would have the oldest, the most EPIC and monumental stones. And what else has the ability to say “EPIC” besides a stone that’s more than a thousand years old?

This led to me a book entitled “Working with Limestone: The Science, Technology and Art of Medieval Limestone Monuments” by Vibeke Olson, one of the few English language books on large-scale medieval artistic production and stone studies.


Page 76:

“The French plain, which extends to the north of Paris, is made up of marl, clay and sand, on which the basilica of Saint-Denis and the medieval city that surrounds it were constructed. The Seine flows into an alluvial plain 1,200 m to the west of the basilica. To the north, the Pinson and Montmorency hills edge the horizon. Like the Montmatre and Belleville hills to the south of Saint-Denis, they are formed of gypsum, marls, clays, and Fontainebleau sand/sandstone layers, with the Montmorency cavernous siliceous limestone outcrops at the summits. Upstream, in the valley of Croult, from Garges-les-Gonesse 5km to the northeast of the basilica, the Saint-Ouen lacustrine limestone and the Beauchamp sand/sandstone can be found close to the surface.

Consequently, the material abundance near the city was an important source of local quarry stone and allowed the production of mortar, tiles and plaster. Only the building stones were not available locally and had to be imported. Fortunately the Paris basin is composed regionally of an excellent building stone known as Lutetian limestone (called Calcaire grossier)…”

It is this Calcaire grossier or soft limestone which many parts of the city of Paris was built with. The rest of chapter 5 elaborates more about the quarries and the Lutetian limestone known as the “Paris stone” (pierre de paris) that is found in all the medieval monuments.

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Image Source: “Working with Limestone: The Science, Technology and Art of Medieval Limestone Monuments” by Vibeke Olson

Lutetian limestone was extracted from a few parts of the banks of the Seine during the medieval period, and also in large quarry centers along the Oise river. The stone that was mined there was also called “Oise Stone (pierre de l’Oise) which was used in the nineteenth century and is still actively mining and exporting this stone to other countries and for the restoration of historical monuments. Limestone from these areas can sometimes be very hard or quite soft. Interestingly, in buildings like the basilica of Saint-Denis, they arranged it so that the hard stones faced outwards and the softer stones faced the interior. [One more stone of note is a kind of white hard chalk known as Vernon Stone (pierre de Vernon), mined from a spot approximately 110km from Saint-Denis, which was actually used for the foundations of the building. This Vernon Stone is also used in Normandy building sites. I add this additional fact in just for completeness.]

A slight digression of note at this point would have to do with another area also full of limestone – Cornwall and Lyme Regis. I have a certain interest in the coastline of Lyme Regis due to it being the setting of one of my favorite novels – John Fowles’ “The French Lieutenant’s Woman”. Now, although later searching reveals that the origins of the name “Lyme Regis” comes from its proximity to a River Lym as first named by the Romans, I must admit that for some time I had thought the “Lyme” in “Lyme Regis” was related to the abundance of limestone (lime being calcium oxide) and all of its ancient fossils in the region. Many famous dinosaur fossils were found on the coasts of Lyme Regis (some by the famous palaeontologist Mary Anning), and limestone itself is a kind of rock that is likely to have been made from the skeletal remains of all the little marine organisms that teem in the seas. It is famously noted that Jane Austen had visited it three times and wrote it into her final novel, Persuasion. I am not so much an Austen fan to have noted this, but I learnt of the fictional fall of her character of Louisa Musgrove from Fowles’ book, where the fictional victorian character of Ernestina notes, while fictionally walking down a flight of stairs that exists in reality, that “these are the very steps that Jane Austen made Louisa Musgrove fall down in Persuasion‘. Oh! What a dramatic accident! Apparently even Lord Tennyson was said to have commented (when he arrived in Lyme Regis):

“Don’t talk to me of the Duke of Monmouth. Show me the exact spot where Louisa Musgrove fell!”

Speaking of accidents, if one goes about searching for tours to either the quarries or the coast, one will see information stating that some areas and sites are considered unsafe for long visits because of the possibility of “geological accidents”. This is a little vague sometimes. This particular phasing of words attracted me, because on one hand I knew it was used to describe true accidents in the sense of the word, like if parts of the rocks dislodged themselves and hit someone, that would be a geological accident. Or, if someone fell off whilst in the midst of a geological study, perhaps it would be called a geological accident. But then again, in its most obvious form, the term could also refer to geological anomalies such as fissures or faults. Last of all, geological accidents could also refer to the accidents by little animals and creatures that were compressed into the rocks to form fossils. So it is a pretty flexible term. Perhaps all of the above scenarios illustrate the dangers of being near rocks:

Geological Accidents:
(1) being hit by falling rocks
(2) falling off rocks
(3) earthquakes and other actual geological events
(4) becoming compacted and eventually fossilised, by accident

These are just meandering collections of facts at this point, so let’s go back to the city of Paris. I found in another article (in french) that notes that since a lot of Paris was built from materials from Paris itself, the mining of gypsum and limestone in the city also gave rise to huge underground caverns and “catacombs”. “Les Catacombes de Paris”! The article also seems to be describing how the catacombs are built in the process of mining for limestone. I wonder if I can visit them?

I’ve also found another link to a “Stone heritage centre in Saint Maximin, which is said to have been the source for stones that were “used to build Les Invalides, the Palais Bourbon and the Place de la Concorde”! Their simple website also writes: “The Maison de la Pierre (“stone-heritage centre”) of southern Oise seeks to develop “stone tourism”: cultural and industrial tourism centred around the department’s important stone heritage…”

French people! I’ve never heard of “STONE TOURISM” before – is this phrase the result of some wonky french-to-english translations? Or are they attempting to come up with a new, cutting-edge tagline here? Either way, I don’t mind going out to visit Oise as a Stone Tourist, as long as I get to witness some geological accidents along the way. Yeah baby.

See also:
Where Exactly did Louisa Musgrove Fall?
Les Anciennes Carrieres Du Calcaire Grossier a Paris
Comité Français d’Histoire de la Géologie