Caked in centuries-old grime, a rock of turquoise could hold the key to that rarest of events in Asian political affairs: co-operation between Beijing and the Dalai Lama.
Valued at up to an improbable US$100 million, the gem - believed to be the largest in existence - had been through a series of auctions and even a Paris flea market before being spotted recently by an eagle-eyed collector in a catalogue for a private auction.
"The stone has changed hands many times in Europe, with many people failing to realise what it was, since they had never seen a [rock of] turquoise this large," says Mike Gladstone, the spokesman for a group of British collectors and businessmen who have come together to try to get the stone repatriated. Realising it was probably the long-lost property of a Tibetan monastery, the group - whose number and names are being kept a closely guarded secret - each handed over £7,000 (HK$83,000) to save the piece from the jeweller's saw.
They have now handed the gem over to the British representative of the Dalai Lama with one wish - to see it reunited with its rightful owners, a mission far easier willed than executed.
THE GEOLOGICAL WONDER, weighing an estimated 16,500 carats, is clearly a paragon specimen and a survivor. Most large rocks of turquoise sooner or later end up facing a blade, to be sawn into small gemstones, which maximises value.
"It is a wonder as to how this stone has survived this long intact," says Gladstone.
Tibet is rare in that its indigenous Buddhist population reveres such large gems because the spiritual value of turquoise is worth far more than a cheque from an auction house. And because the region is remote and regularly sealed off from the outside world, such a prize there is far more likely to stay out of the clutches of gem dealers.
"Jewellers have advised that if sold intact with the authority of the Dalai Lama and verified as the largest and finest specimen of turquoise in the world, it might make as much as US$100 million at auction, although if another turquoise of similar quality and larger size were discovered, it would be worth much less," says Gladstone.
Historians and geologists are relishing the find, but offer more modest estimations.
"To make an accurate comment, our mineralogy experts would need to actually examine the specimen; however, they suggest [from the photographs] that the valuation you have mentioned does seem very high," says Lyndsey de Valmency, of London's Natural History Museum. "We suggest more in the region of £10,000 to £500,000 [as it looks to be about 30kg], perhaps reaching £1 million if traced back to Tibetan culture."
"This is certainly an impressive natural specimen," says Michael Willis, of the Department of Asia at the British Museum in London. "As to its age, there is really nothing to say as the item has not been worked [studied]. The provenance will depend entirely on relevant documents that can be found, if [there are] any."
A distinct, blackened waxy residue - a pungent mixture of yak and other animal fats, and incense from candles commonly found in Tibet - is engrained deep in the nooks and crannies of the stone, offering the strongest clues as to its provenance. In a Tibetan monastery high in the Himalayas, such a stone would be known as an "eye to heaven" and serve as a focal point of worship and prayer.
Turquoise has been prized as a gem and ornamental stone for thousands of years, owing to its unusual blue-green hue. It is a hydrous (water-containing) phosphate of copper and aluminium, a chemical cocktail potent enough to give amateur alchemists palpitations and send professional gem collectors scurrying for their calculators. The finer the grade of turquoise, the higher the value and degree of reverence afforded it (though in recent times, as with most other opaque gems, turquoise has been devalued by the introduction of synthetic imitations).
It is known by many names but the word "turquoise" is derived from an old French word for "Turkish", as it was brought to Europe in the 16th century through Turkey from mines in Iran.
Much of the world's turquoise is thought to have originated in Iran, where it has been mined as a gemstone for 7,000 years. The Iranians named it " phirouzeh". Its pastel shades have endeared the mineral to many great cultures: it has adorned the rulers of Ancient Egypt, the Aztecs, Persia, Mesopotamia and the Indus Valley.
This huge rock may well have served as an object of worship in several ethnic communities across many regions and over many millennia before finding its way through the network of silk routes to the Himalayas. Then again, it could have been mined in Tibet itself, a landscape that has pockets of the jewel peppered in the layers of rock that make up its mineral-rich mountains and river valleys.
Turquoise has been revered and worn by the people of the Himalayas for thousands of years. It is called gyu - pronounced "yu" - and many Himalayan people still wear turquoise in one form or another.
Cherished as a sky stone brought to Earth from the heavens, pieces of it are given to Tibetan children in the belief that it will keep them from falling from the slopes and mountain ridges of their homeland. As they grow older, they tend to adhere to the conviction that the bigger the stone the greater its power. Turquoise is thought to preserve family wealth and bestow ritual and medicinal benefits.
Now the mission to have this special stone returned to its rightful place is underway, albeit slowly, given the region's geopolitical sensitivities. Gladstone handed the gem over to Thubten Samdup, the Dalai Lama's representative in Britain, at a low-key ceremony in London just before New Year.
"I have just returned from India and consulted with senior monks about what best to do with the stone," Thubten Samdup tells Post Magazine. "I showed them copies of the photos and we all agree the stone should be returned home.
"If we can find out exactly which monastery this stone comes from, we will try and contact the lamas in charge and try and return it to its rightful place. We may have to go through the Chinese authorities."
He adds: "Most important is that we believe it would be something the Chinese tourism bureau in Tibet would be receptive to, as it would be a great draw as a historical relic. But right now, as most of the world knows, our relationship with the Chinese is difficult. We are prepared to approach them and co-operate fully, if possible."
Armed with copies of the photos, several Tibetan monks have turned sleuth and are trying to discover where the stone came from. That might prove impossible, however. Since 1949, the majority of the 6,000 known Tibetan Buddhist monasteries have been destroyed.
Official figures from China claim there are now 1,700 "religious sites" in Tibet. There is, according to officials with a customary fixation on number crunching, one temple or monastery for every 1,600 people.
It is not clear whether the records detail religious sites only in the western part of Tibet, known as the Tibet autonomous region, which is smaller than historical Tibet as it existed before the Chinese invasion.
Some of the most famous monasteries, however, have survived, including the eighth-century Samye Monastery in Shannan prefecture and the iconic, 1,300-year-old - and now under tight 21st-century surveillance - Jokhang Temple, in the capital, Lhasa.
Given the diplomatic stand-off and hyper-tense relations between Beijing and the Tibetan government-in-exile, based in Dharamsala, India, establishing lines of communication between historians on all sides and sharing information that could facilitate the repatriation of the stone might well be a work in progress for the foreseeable future.
The brakes of bureaucracy do, however, offer more time to explore how the stone ended up in Europe. Was it a light-fingered member of the British Indian expedition forces that invaded Tibet in 1903 and 1904 who made off with it, perhaps as a memento? An alternative theory is that the gem was smuggled out of Tibet by Chinese forces after the 1949 invasion and then sold countless times before finding its way to Europe.
"We believe the second possibility is more likely," says Gladstone, "because one of my colleagues recalls seeing the gem featured in a black and white documentary about Tibet while it was still in situ."
That 1950s documentary was believed to have been made by the BBC but no records of its existence can be found.
Requests made to China's Ministry of Foreign Affairs for official views on the stone and its repatriation have gone unanswered.
"In the long term, if we cannot return it, my dream is to open a small museum here in London where we can exhibit Tibetan artefacts," says Thubten Samdup. "There are many relatives of members of the British Empire who travelled to Tibet in the early 1900s and even in the 1800s, and who returned with Tibetan artefacts. Many have said they would donate to such a museum.
"Until then, we are going to approach one of the main museums in London and see if we can loan it to them so that the general public can see this magnificent stone in a place where it is properly cared for in a secure location."
For now, the stone is being kept in a safe place, the mysteries of its past and future, its true worth and its rightful ownership locked away with it.