Through The Sandglass

Black sands, black crystals, and a green queen

 
Pelabuhan Ratu, a sweeping beach on the south coast of Java pounded continuously by the breakers of the Indian Ocean. A popular destination, but one that I have not visited – today’s feature comes courtesy of, and with thanks to, Carol Banks, the latest recruit to my growing army of sand-snatchers.

Pelabuhan Ratu means “Queen’s harbour,” and the place comes with myths and legends galore – but more of that later: for now, the sand. The most popular and developed part of the long beach is a typical tropical white, but great stretches are also gloomily black and less attractive – except to an arenophile, for this is a lovely sand.

I chose the Google Earth image above to show the less-developed section, the river clearly bringing its cargo of black sands down to the coast. When the sand is wet, it is truly a dark charcoal-grey colour, but dry it out and it takes on a speckled brown and grey character – not particularly attractive at first glance. But look closely, and you will see transparent quartz grains, glittering like diamonds amongst the dull fragments of dark volcanic rock. Then there are the grains of the local limestones, together with a few shell fragments, shattered by the surf.

Looking more closely, those grains of transparent volcanic quartz really are beautiful:

 
A number of them, dramatically the one at the upper right, show conchoidal fractures. These are where a material breaks along curved surfaces, often complex and rippled, very much the form of a mussel shell, hence the name (from the Greek for mussel or cockle). This behaviour is typical of amorphous materials such as glass and its natural volcanic version, obsidian – it’s this kind of fracturing that is exploited in the making of obsidian and flint tools. Strictly amorphous materials such as glass have no internal structure to guide fractures; this is not true of quartz, but its mineral structure, and the strength of the bonds between the silicon and oxygen atoms, make it behave very much as if it were amorphous.

The apple-green jewels amongst the grains are the mineral olivine, a common constituent of the kinds of volcanic materials of which Java is constructed. Shine the microscope light through the sand, and the glowing glory of these grains is revealed:

But, in the first group of microscope photos above, there are also very distinctive tiny black grains, clustering together, looking vaguely metallic, and often of a very regular, geometric, shape. What are they? Well, the answer is easily discovered by passing a magnet over the surface of the sand – these little grains defy gravity and hurl themselves upwards on to the magnet’s surface, reasonable behaviour for magnetite.

Magnetite is an iron oxide, chemical formula Fe₃O₄, and is another common constituent of the local volcanic rocks; it’s the most magnetic of all minerals, and is the key to the lodestone, used for early compasses. Left free to fulfil its ambitions, magnetite can form large clusters of glorious crystals such as this specimen, up to ten centimetres across, from one of the mines in St. Lawrence County New York, and in the collection of the New York State Academy of Mineralogy. Unfortunately, since it is a valuable source of iron, magnetite has a social dark side: because it is heavy, the waves of the beach concentrate the grains into placer deposits, and, along the south coast of Java these have been the source of sometimes violent conflicts between developers and local farming communities. But back to the bright side of magnetite, so to speak.

Because these grains do form placer deposits, a little amateur panning in the kitchen separated them out from the lighter grains (I could, of course, have used my magnet, but that wouldn’t have been so much fun). Here are some family portraits:

The amazing thing is that so many of these grains are hardly worn at all, and their original crystal shape is preserved. Look at the one that seems like two pyramids stuck together – that’s the original octohedral form of the mineral, a single, almost perfect, crystal of magnetite. Raw diamonds are often octohedral, but these grains are just humble iron oxide – beautiful nevertheless, don’t you think?

So, what about the queen whose harbour, or bay, is Pelabuhan Ratu? Well, this stretch of the Java coast is the haunt of Nyai Roro Kidul, the mythical Queen of the Indian Ocean in these parts, and a shape-shifting spirit of Javanese and Sundanese folklore. She is, of course, beautiful, but she is powerful, able to take your soul on a whim. Various versions of the legend describe how a beautiful princess was struck with black magic by a jealous rival in the palace and developed a horrible skin disease. She fled to the ocean and plunged into the waves, where she was cured and crowned queen by the marine spirits and demons. Her sacred colour is green, and there is a local belief that wearing green will anger Nyai Roro Kidul – so, arenophiles, should you visit Pelabuhan Ratu, please choose your outfit with this in mind.

Can we please not blow up coral reefs?

BEFORE: A Pinnate batfish swimming among other fish in Tatawa Besar in the waters of Komodo islands, Indonesia. AFTER: damaged coral reefs in the water of Tatawa Besar, Komodo islands, Indonesia. [Robert Delfs/Michael W. Ishak]

I admire corals – not only for their beauty, diversity, and the communities they harbour, but also for their fortitude. Notwithstanding our (justified) concern over the future of coral reefs today, they are extremely ancient critters and have survived for hundreds of millions of years through thick and thin. And when you consider the number of mass extinctions that have occurred in our planet’s turbulent history, those are extreme thicks and very thins.

Let’s face it, corals represent yet another example of things about which what we do know is but a fraction of what we don’t – see, for example, recent revelations on their survival skills. It’s only a few months since I had the pleasure of visiting parts of eastern Indonesia and, amongst the many memories, snorkelling around the glorious coral reefs of the Komodo Islands ranks right up there:

 
So, you can perhaps imagine my horror when recently, in the Jakarta Globe, courtesy of Associated Press, I saw the image at the head of this post and read the following story:

Fishermen Blast Premier Dive Sites Off Indonesia
Jacob Herin | April 20, 2012

Komodo Island, Indonesia. Coral gardens that were among Asia’s most spectacular, teeming with colorful sea life just a few months ago, have been transformed into desolate gray moonscapes by fishermen who use explosives or cyanide to kill or stun their prey. Dive operators and conservationists say the government is not doing enough to protect waters off the Komodo Islands in eastern Indonesia. They say enforcement declined greatly following the exit of a US-based conservation group that helped fight destructive fishing practices. Local officials disagree, pointing to dozens of arrests and several deadly gunbattles with suspects.

Michael Ishak, a scuba instructor and professional underwater photographer who has made hundreds of trips to the area, said he’s seen more illegal fishermen than ever this year. The pictures, he said, speak for themselves.
When Ishak returned last month to one of his favorite spots, Tatawa Besar, known for its colorful clouds of damselfish, basslets and hawksbill sea turtles, he found that a 200-square-meter reef had been obliterated. “At first I thought, ‘This can’t be right. I must have jumped in the wrong place,’” he said, adding he swam back and forth to make sure he hadn’t made a mistake. “But it was true. All the hard coral had just been blasted, ripped off, turned upside down. Some of it was still alive. I’ve never seen anything like it.”

The site is among several to have been hit inside Komodo National Park, a 500,000-acre reserve and U.N. World Heritage Site that spans several dusty, tan-colored volcanic islands and is most famous for its Komodo dragons — the world’s largest lizards. Its remote and hard-to-reach waters, bursting with fluorescent reds and yellows, contain staggering levels of diversity, from iridescent corals and octopuses with lime-green banded eyes to black-and-blue sea snakes.
They are supposed to be protected, but fishermen are drawn there by locally popular fish like fusiliers and high-value export species like groupers and snappers. Fishermen can be seen in small wooden boats, some using traditional nets or lines. Others have been captured on video blasting sites with “bombs” — fertilizer and kerosene mixed in beer bottles. Breathing through tubes connected to air compressors at the surface, young men plunge to the bottom and use squeeze bottles to squirt cyanide into the coral to stun and capture fish. Dive operators are increasingly seeing dead fish on the sea floor or floating on the surface.

“The biggest problem is that fishermen seem to be free to come into Komodo, completely ignoring the zoning and resource use regulations,” said Jos Pet, a fisheries scientist who has worked with numerous marine conservation groups in the area in recent years. He said they are “quite simply fishing empty this World Heritage Site.”

Sustyo Iriyono, the head of the park, said problems are being exaggerated and denied claims of lax enforcement. “It’s only part of the black campaigns against us by those who are hurt by our rules and orders,” he said without elaborating. He said rangers have arrested more than 60 fishermen over the past two years, including a group of young men captured last month after they were seen bombing waters off Banda island in the western part of the park. One of the suspects was shot and killed after the fishermen tried to escape by throwing fish bombs at the rangers, Iriyono said. Three others, including a 13-year-old, were slightly injured.

“You see?” said Iriyono. “No one can say I’m not acting firmly against those who are destroying the dive spots!”
He added that the park is one of the few places where fish bombing is monitored with any regularity in Indonesia, a Southeast Asian nation of more than 17,000 islands.

Divers, however, say enforcement has dropped dramatically since 2010, when the government reclaimed sole control of operations. For two decades before that, The Nature Conservancy, a U.S.-based nonprofit, had helped the government confront destructive fishing practices there. “No-take zones” were created, protecting spawning areas, and coastal areas also were put off limits. Patrols using park rangers, navy personnel and local police were key to enforcement.
In 2005, the government gave a 30-year permit to Putri Naga Komodo, a nonprofit joint venture company partially funded by The Nature Conservancy and the World Bank to operate tourist facilities in hopes of eventually making the park financially self-sustaining. Entrance and conservation fees — just a few dollars at the time — went up several tenfold for foreign tourists. With around 30,000 local and international visitors annually at the time, that would have given the park a budget of well over $1 million, but outraged government officials demanded that the funds go directly into the state budget. The deal collapsed in 2010, when Putri Naga Komodo’s permit was yanked. “They had no right to directly collect the entrance fees from the tourists,” said Novianto Bambang, a Forestry Ministry official.

Dive operators and underwater photographers have asked The Nature Conservancy and similar organizations like WWF Indonesia, to return to Komodo and help with conservation efforts there. Nature Conservancy representative Arwandridja Rukma did not address that possibility, saying only that the organization operates in Indonesia upon the invitation of the government.

Yes, this is horrifying: blowing up coral reefs or injecting them with cyanide is utter lunacy. But, as always, it’s not a simple issue. Unregulated and chaotic fishing have depleted natural stocks, and, regardless of what proportion of explosive mayhem is perpetrated by outsiders as opposed to locals, the fact is that the inhabitants of the Komodo islands, if not actually poverty-stricken, live very lean lives. These are some of our photos from the town of Komodo, the largest concentration of the population. These people have to live, and fishing is their main – virtually only – means of doing so. These kids deserve food, an education, a life.

After I read this piece, by yet another twist of serendipity, I received an email from Richard Bready. Richard is a frequent commenter on this blog, always adding a fascinating, and often provocative, dimension to the posts - and he is, so far, my only guest poet. It seems that, from the post on the European sand belt, he had been following a trail of links on the subject of geoconservation, and come across the site of Ashoka Changemakers – whose purpose is to create “opportunities for organizations, corporations, and individuals to drive meaningful and measurable social change.” They are supported by, amongst others, the Rockefeller Foundation and the Bill and Melinda Gates Foundation. Never having come across this initiative, I followed up, specifically, as Richard directed me, on their coastal program, and their “Geotourism Challenge 2010: Places on the Edge - Saving Coastal and Freshwater Destinations.” Now this competition has been supported by the National Geographic, the Inter-American Development Bank, and the latter’s Multilateral Investment Fund, and there is an understandable focus on Central America. But what fascinated me – and is of great relevance to the topic of this post – were two of the three winning initiatives:

1. Coral Gardens - Living Reefs

Reefs provide food and income for coastal communities and are a foundation of tourism, producing white sandy beaches and protecting shorelines. My idea has been to actively involve communities and the tourism industry in planting and caring for corals, with the dive industry trained to care for dive sites, and with resorts taking on trained "coral gardeners". Guests can also become involved and learn about reefs while they help plant corals and garden the reefs, giving something back to the destination and to the planet.

Go to the full description to read the details – this arises directly from the passion of an individual.

Then, there was this winner – deeply relevant to Komodo, and again the idea of an innovative individual:

2. Development of economic partnerships between artisanal fisher folk and tourism operators

Project will create economic partnerships/opportunities between artisanal fisher folk and the tourism sector by constructing a locally-supported fisheries co-op for certified, sustainably caught products and direct marketing strategy with local hotels/restaurants. Project will construct a marine research center that contributes to responsible tourism development/heritage protection by promoting local SMEs.

It struck me that these projects address exactly the issues that the reefs and the inhabitants of the Komodo Islands are facing – and that support for them by Ashoka Changemakers is admirable. The concept of translating these ideas into an Indonesian context is, as the article above so depressingly shows, a huge challenge. But Komodo is a National Park, and has been a World Heritage Site since 1991. If anywhere fits the definition of an “ecotourism destination,” and a prime candidate for geoconservation and biodiversity preservation, Komodo is it. But people live there and must be active participants in - and beneficiaries of - any progress. It may be difficult, but we can’t accept that it’s impossible, and surely somewhere there are people with the vision, the passion, and the expertise to make something like the initiatives described above actually work in Komodo. Please.

 

Sunday sand: Ngobaran

 
Sand from perhaps the smallest “beach” that I have visited and sampled. One of the items on the varied agenda of a recent long weekend in Central Java (varied in the way that part of the world uniquely and fascinatingly offers) was an exploration of a few of the small beaches on Java’s south coast. My intention was to avoid the crowds at the large, popular, beaches (the day of the visit being Sunday) and find a couple of the small coves that nestle between the spectacular cliffs of that part of the coast. The first destination was Ngobaran – and it certainly fulfilled the criterion of a “small beach.” Dramatic and rugged limestone cliffs face the incoming waves of the Indian Ocean, and the constant kinetics of the place leave little opportunity for sand grains to gather. But, in a small area sheltered by massive boulders, a patch of coarse sand had accumulated:

And here it is, the usual mix of local ingredients, including many of the little spherical forams, so common in these parts and looking for all the world like natural ball-bearings:

In detail, the varied patterns and textures are endless:

 
And, as further geo-entertainment, the weathering of the limestone boulders produced a starkly rugged form of tafoni: 

And, as I watched the Indian Ocean waves roll in, I was inspired to play with the the high-speed burst function of my camera and experiment with catching the action – nothing to do directly with sand, so please excuse my self-indulgence:

 

An artist's view of Holland's inland sand seas

A while ago, I wrote a couple of posts on “the European sand belt, a great swathe of lowlands covered, more or less, by aeolian sand deposits originating from the chaos left behind by the retreat of the Ice Age glaciers,” the second with a focus on the Dutch dunes of Hulshorst in the Veluwe region. Recently, I was delighted to see a new comment on this post, from Francien Solitar, who wrote:

My stepdad was P.H.Mullaard. He lived in Ermelo and painted the Hulshorster zanddunes in more than one painting. (see: Mullaard.com) He spoke with a forest keeper there and he was told that, when there is a thunderstorm in the area, there seems to be an unusual amount of lightning flashes that hit the dunes and make craters in the ground.

I immediately went to the website that Francien is developing, showcasing Piet Mullaard’s works, and at the same time took the liberty of contacting her by email. This is yet another of those immensely satisfying “out of the blue” contacts that arise through the blog, and Francien responded immediately and graciously. She lived in the town of Ermelo (see the image below), and was a schoolteacher there before later emigrating to Canada in 1976.

As the website describes, “Piet Mullaard was born in Rotterdam, the Netherlands. He lived and worked in Hillegersberg, Ermelo, Groningen and Bilthoven. He was an autodidact and worked as a painter and sculptor. He left a collection of about 150 paintings and 25 sculptures. Most of the collection is now in Canada.” Francien very kindly gave me permission to reproduce some of her stepfather’s paintings of the Dutch sand belt; the painting at the head of the post is  Sand Dunes at the Veluwe (1947, oil on canvas, 126 x 100 cm). Below are Uprooted Trees in the Sand (1946, oil on canvas,88 x 64 cm) and The Small Drift Sand (1946, canvas, 60 x 40 cm).

 

These are wonderfully atmospheric paintings in the great Dutch tradition, and a very satisfying link between landscapes, geology, sand, and art – thanks, Francien, for drawing our attention to your stepfather’s work!

 

[Photo with the Google Earth image from the Ministerie van Economische Zaken, Landbouw, en Innovatie website.]

Caption competition?

Well, sorry, no, this is just too easy: guess “World’s biggest bunker!” or “World’s biggest sand trap!” (depending on which side of the Atlantic your golfing perspective comes from), and you’d be – predictably – spot on.

When I first saw this image in our local paper, it seemed to be described as an episode in the current Abu Dhabi tournament, and this struck me as being one hell of a golf course. Only closer reading revealed that this was a promotional event in which two players were helicoptered out into the dunes (sorry, bunkers) of the Liwa Desert. As reported in the UK’s Daily Mirror:

Luke Donald will have no fears about playing out of the sand at this week’s Abu Dhabi HSBC Golf Championship after he successfully tackled the "world’s biggest bunker" – a mammoth dune in the Liwa Desert.

In Liwa, Donald was joined by triple and defending Abu Dhabi champion, Martin Kaymer, as the awe-struck pair stood among 250-foot sand dunes at the entrance to Rub Al Khali (Empty Quarter) - the world’s largest uninterrupted sand mass.

Donald used the stint in the desert to try out some new clubs ahead of the tournament, which features some of the world's best players.

Kaymer and Donald headline an Abu Dhabi field that is the strongest ever assembled at a Middle East tournament.

Or, from Today’s Golfer (where the image comes from):

Donald splashes out of world's biggest sand trap

World number one, Luke Donald, will have no fears about playing out of the sand at Abu Dhabi Golf Club for this week’s Abu Dhabi HSBC Golf Championship, after the Englishman successfully tackled the world’s biggest ‘bunker’ – a mammoth dune in Abu Dhabi’s Liwa Desert, the world’s largest uninterrupted sand mass.

In Liwa, Donald was joined by triple and defending Abu Dhabi champion, Martin Kaymer, as the awestruck pair stood amongst 250-foot sand dunes at the entrance to Rub Al Khali (Empty Quarter) - a desert made famous by British explorer Wilfred Thesiger’s 1940’s crossing and immortalised in the timeless book: Arabian Sands.

“Well that was no ordinary sand trap!” said Donald, who became the first player in history to top both the PGA and European PGA money lists last year.

“When you spend the vast majority of your time on the course, it’s easy to forget that Abu Dhabi is surrounded by such an enchanting desert landscape. Truly, I was awestruck at the gigantic enormity of it all.”

Interestingly, if you look closely at the crest of the dune behind Kaymer in the photo, you will see that it is hardly pristine – there are tire tracks across it. This is explained by the following image of an interruption to the photoshoot by local traffic:

 
This desert is spectacular, and you can see where the idea for this promotion came from (although, at the time of writing, the experience does not seem to have provided either player with a cutting edge or competitive sand wedge in the actual tournament).

 

[Photos Getty Images, websites linked above, and http://ca.sports.yahoo.com/golf/pga/photo?slug=8addeb5fe5448b221dbd13491442a3b3-getty-137681196]

Sunday Sand Scene

OK, the Paris-Dakar rally is controversial, but this is simply such a spectacular image.

 

[Peru, photo Reuters/Philippe Desmazes]

Sandstorm

It begins with a dance. The wind playing games with the sand and the sand playing along. Ephemeral flurries, a shape-shifting fabric of turbulence, scurrying grains. It’s a compelling and alluring show, but, at the same time, as the wind gathers, the air begins to become oppressive and the brilliant blue sky takes on a threatening dullness as the cargo of dust changes the spectrum. The ephemeral flurries become continuous sheets of sand hurtling across the desert surface, assailing everything in their path. The sun is dimmed.

And then suddenly, seemingly out of nowhere, this streaming chaos turns into the full fury of a sandstorm, a full-blown assault, threatening everything.

Ahmed Hassanein Bey was a highly educated Egyptian, a diplomat and tutor to the king, but a man with deep Bedouin roots. He was the first to cross the Libyan Desert, from the Mediterranean to Sudan in a perilous eight-month journey by camel in 1923; in his extraordinary account of this journey, The Lost Oases, he describes the frequent sandstorms encountered:

It seems as the whole surface of the desert were rising in obedience to some upthrusting force from beneath. Larger pebbles strike against the shins, the knees, the thighs. The spray of dancing sand grains climbs the body till it strikes the face and goes over the head. The sky is shut out, all but the nearest camels fade from view, the universe is filled with hurtling, pelting, stinging, biting legions of torment...It is as though some great monster of fabled size and unearthly power were puffing out these hurtling blasts of sand upon the traveller’s head. The sound is that of a giant hand drawing rough fingers in regular rhythm across tightly stretched silk.

When a sandstorm comes, there is nothing to do but to push doggedly on. Around any stationary object, whether it might be a post, a camel or a man, the eager sands swiftly gather, piling up and up until there remains only a smoothly rounded heap. If it is torture to go on, it is death itself to halt.

During my expedition to the Western - or Libyan – Desert a few years ago, we were assailed by two full-blown sandstorms, the second one far worse than the first. In this age of motor travel, stopping is, unlike in the days of camel transport, the only option, unless frosted windscreens and severe testing of the seals of mechanical components are wished for. The system, well-practised by our drivers and guides, is to circle the wagons – form the vehicles into a square and lash large pieces of heavy fabric between them in an attempt to provide shelter. The attempt can only be partially successful - Hassanein Bey again:

The storm drives the sand into everything one possesses. It fills clothes, food, baggage, instruments, everything. It searches out every weak spot in one’s armour. One feels it, breathes it, eats it, drinks it – and hates it. The finest particles even penetrate the pores of the skin, setting up a distressing irritation.

Our real humdinger of a sandstorm, one that our guides ranked among the worst they had experienced, was in the White Desert, an iconic and spectacular landscape of white limestone sculptures, created by the wind with sand as its tool.

The wind had been gathering all afternoon, the air becoming oppressive, and the sky increasingly dull. As the storm gathered, I had stupidly attempted to put up a tent, but had to give up with the job only half-done. Determined to make the most of the experience, I huddled into the doorway of the semi-erected tent, wrapped a long piece of blue-dyed Moroccan cotton fabric around my head and face in an amateurish imitation of a Tuareg, and took out my notebook. The earth was on the move. As miniature sand dunes migrated past, and the hissing, spattering sound of the grains grew in volume, the burial process began. Piles of sand accumulated rapidly against my legs and began to weigh down the defenceless side of the tent. I tried to scribble down my account, but even a pencil had problems and sand accumulated in the hinge of my notebook (grains still fall out when I open it today). I watched some of my companions trying to put up their tent, and the drivers scrabbling to get some kind of shelter lashed down between the Landcruisers. There were no camels by which to judge visibility, but only during the occasional brief lull in the onslaught could this nearby scene be discerned with any clarity.

It was during one of these brief moments that, perhaps driven to dementia by the granular onslaught, I completely lost control of my senses and took out my camera.

There were two results of doing this – one photograph, and, ever after, a scratching sound when adjusting the telephoto lens.

I gave up, and battled my way to the shelter where my companions huddled, sharing the now very limited supplies of single malt whisky. Somehow, amazingly, in this mayhem, the cooks produced food; sleep that night was intermittent, but I remember being awakened at one point because the noise had stopped. And dawn was miraculous. There was no sign of the storm (other than the piles of sand marking buried tents), but rather a crystalline clarity, a sense that the desert had been cleansed.

 
And, suddenly, there was this colourful and fearless little bird strutting about in the sand – where could it possibly have sheltered overnight during the storm?

 

This was a staggeringly beautiful landscape, but one completely different from the previous day: immeasurable, unimaginable, volumes of the earth’s fabric had been moved, wholesale, from one place to another.

 

[This is my contribution to The Accretionary Wedge, December 2012, hosted by Ron Schott, with the theme “The Most Memorable Geological Event That You’ve Directly Experienced.”]

So what on earth are these people looking at?

 
A somewhat blurry photo of a beach at night, clearly some kind of alcoholic beverage in the hands of at least two of the people, one of whom seems be in a state of some excitement, the other two staring intently at – the sand. What is the story behind this strange image?

I described a while ago the wonderful pink sand beach on Komodo Island, as we experienced it during the day. Returning at night for a beach barbecue, we would find that it had another surprise in store for us. The excited person in the photo is François, a delightful Swiss fellow traveller with whom, together with his wife, Ursula, we shared many enjoyably garbled bilingual conversations during our trip (well, garbled on our part). That evening we were loitering about enjoying the place, the wine and the company, when we heard an excited exclamation from  François who seemed to be performing some kind of bizarre dance, stomping in the sand and pointing at his feet (while, of course, cleverly maintaining the stability of his beverage). Deciding to humour him, we wandered over – to find that his stomping was producing endless flashes of brilliant blue light amongst the sand grains.

The result was a whole crazy group of people leaping around, stamping on the sand and shouting in delight – bioluminescence! Not the easiest phenomenon to photograph, but François just sent me this image, which I have adjusted slightly so that the sand grains are visible for scale:

My (not particularly well-informed) guess is that we were witnessing bioluminescent dinoflagellates, single-celled marine plankton whose name derives, dramatically and bilingually, from the Greek for “whirling” and the Latin for “whip,” reflecting aspects of their morphology. Many of them are – like the majority of marine organisms – capable of bioluminescence, mostly of this iridescent blue colour, and it was some of these critters whom the waves were bringing in that evening and providing our light show in the sand. Their individual displays were brief, only slightly more than a flash, and induced by the agitation of our pounding of the sand – apparently it is the deformation of the cell that triggers the chemical reaction. Bioluminescence is an extraordinary phenomenon, “generated by an enzyme-catalyzed chemoluminescence reaction, wherein the pigment luciferin is oxidised by the enzyme luciferase… Most marine light-emission belongs in the blue and green light spectrum, the wavelengths that can transmit through the seawater most easily.” (Sciencedaily). It seems likely that dinoflagellates use bioluminescence as a deterrent and warning mechanism, but the phenomonenon is not well understood and is the subject of extensive research - for a comprehensive resource, see http://www.lifesci.ucsb.edu/~biolum/ from the University of California, Santa Barbara. And here's a great science fair project outline on bioluminescence, with all kinds of further resources.

The illustration above is from a blog piece by Marko Manriquez, where, fascinatingly, he is proposing an art installation using bioluminescent dinoflagellates; interestingly, I found this at the same time as discovering that the Smithsonian Natural History Museum is currently holding a special exhibition inspired by bioluminescence:“The Bright Beneath: The Luminous Art of Shih Chieh Huang.” The art is inspired by our friends such as the dinoflagellates, but sadly does not feature any of the critters themselves as far as I can tell – but it makes me wish I was in Washington.

I shall end by noting that strange bioluminescent phenomena were on display in other ways that night on Komodo’s pink beach – note the dazzling effects on the head of the old guy next to François in this photograph:

 

 François, many thanks for your discovery, your dance, your photo – and your company.

Abrasive Sunday Sand

 
All in all, it’s been an abrasive week. No, I’m not referring to my day job, but rather an emerging theme that started with my last post on the stories of three indefatigable women and a mystery Gobi sand. So far, there have been two very interesting responses to my question of what the mineral content of this “special sand” might be that made it so prized for polishing jade (and I’m also following up on other suggestions): Howard Allen helpfully defines some constraining criteria in terms of hardness and density (we must be dealing with something heavy enough to form a placer deposit, and hard enough – but not too hard – to polish a tough material like jade). Richard Bready – knowledgeable and stimulating as always – points to the work of a researcher at The British Museum whom I should contact, and sources that mention corundum, quartz, and garnet.

Earlier in the week, I heard from Siim Sepp, a graduate student of geology at the University of Tartu in Estonia, who alerted me to his areno-blog, Sandatlas, which he has been expanding into a wide-ranging and informative source for a variety of geo-topics. Browsing around Siim’s site, I was struck by one of the images in his gallery, above. This stunning sand is from the area of the Emerald Creek garnet district in the panhandle of Idaho, where garnets from sand- to golf ball-size occur in placer deposits that, organised by the Forest Service, can be visited by the public for a “mine your own garnets” day out. Garnets have been used since antiquity as both gemstones and abrasives, and the latter continues to be a widespread application today; Emerald Creek, in addition to being a Forest Service recreational area, is still one of the leading sources of industrial garnets in North America, producing a range of product sizes for everything from serious sand-blasting to fine polishing via water-jet cutting.

There are quite a few different “species” of the mineral group collectively referred to as garnet; they are all silicate minerals (strictly, nesosilicates or orthosilicates), but their composition (and colour) varies, with different sites within the crystal structure being occupied by iron, magnesium, calcium, aluminium, and chromium. Nevertheless, they all belong to a single group because they all have the same crystal form – the crystals are isometric, their internal structural symmetry being that of a cube. In garnets, these highly symmetrical internal building blocks most commonly organise themselves into the overall shape of a dodecahedron, but other related shapes can also form. The combination of colour and symmetry produces some truly stunning crystals, such as this one from Emerald Creek, the big one being 2.5 centimetres across (image from Exceptional Minerals):

 
One particular form, the star garnet, is the State Gem of Idaho; these extremely rare specimens are examples of asterism, the appearance of a luminous star shape as a result of tiny fibrous crystals of the mineral rutile (titanium dioxide) being included in the structure:

Garnets have a torrid geological history, born at high temperatures and pressures deep in the earth’s crustal kitchen, and, as a result, showing up at the surface in metamorphic, or, less commonly, igneous rocks. The garnets of the Emerald Creek district originate from sediments deposited around 1.5 billion years ago, buried, cooked, and rudely ejected back to the surface; weathering has liberated the tough garnet crystals to be concentrated in the stream placer deposits, but the original hard rock has also been extensively mined for not only garnets but a wide variety of minerals and metals.

So, not a solution yet to the Gobi mystery, but, for me at least, an interesting detour from the daily grind.

Extraordinary women–and a Gobi sand question

 
For one reason or another, I have been reading The Gobi Desert by Mildred Cable and Francesca French. In the history of exploration and enquiry into far-flung parts, it’s easy to overlook that regiment of indefatigable women – particularly Victorian - who played extraordinary roles. Perhaps the most celebrated was, of course, Gertrude Bell, whose middle-eastern exploits changed politics and history. But in China, in the first couple of decades of the last century, there were three women, Mildred, Francesca, and the latter’s sister, Eva (Evangeline), who documented the landscapes and culture of that part of the world through quite remarkable travels. Yes, they were missionaries, but they pursued their goals with linguistic skills and a deep cultural sensitivity that resulted in accounts that are distinctly and fascinatingly different from the typical travel writing of the times and have become classics. And the classic of the classics is their description of their thirteen years in the Gobi, “following trade-routes, tracing faint caravan tracks, searching out innumerable by-paths and exploring the most hidden oases. ... Five times we traversed the whole length of the desert, and in the process we had become part of its life."

The story begins as they set out from the fort at what is today called Jiayuguan, the westernmost bastion of the Great Wall. Leaving the western gate, they passed a great mound of earth whose role was to keep out the evil spirits of the desert, and a stone tablet on which were inscribed the forbidding words “Earth’s Greatest Barrier.” Following the Silk Road westwards, they stopped at isolated and insular oases – Shachow, “City of Sands,” Shamen, “Gates of Sand.” These even before they reached the Taklamakan Desert proper.

But one of the things that intrigues me is the following account from their overnight stay in Huei-huei-pu, the “Moslem Tomb Halt,” whose location today I have yet to figure out. While wandering around the village, Mildred stopped at the local shop, where

There was something different here, however, for, in addition to the dull stock of the oasis shopkeeper, this man had a variety of articles made from a fine-grained, light-grey stone which was found near at hand. These were slabs on which to rub down the hard sticks of Chinese ink, and little pots to hold water with which to moisten them. The chief demand, however, was for small pieces to be used as whetstones for knives, razors or scissors, and many a carter passing that way added a hone to his small outfit of traveller’s necessities.

Having made some purchases, Mildred sat down and chatted with the shopkeeper about this and that, but then

I turned to go, and just as I was leaving, I noticed on his counter a jar of coarse grey sand. Taking some of it in my hand, I rubbed it between my fingers testing the quality of the grains, and as I did so I felt there was something unusual about it. “What do you keep sand for?” I asked. “Is there not enough of it by the roadside?”

“This is special sand, Lady,” he said. “It comes from near here but is not found elsewhere in the Gobi.It is so heavy that the wind does not blow it about, and it is the only sand which can be used for one process in the polishing of jade.Though it is hard enough to use even on jade, yet it never scratches the surface. It is very highly valued, and jade polishers send here to get it.”

So there’s my question – does anyone have an idea as to exactly what this highly valued sand might be?