Last Thai Ruby Miner • Red Sky at Dusk • Lotus Gemology

by Richard W. Hughes & Vincent Pardieu, with Michael Rogers, Olivier Segura and Philippe Ressigeac
Red Sky at Dusk  |  Hunting the Last Siamese Ruby Miner

In search of Thailand's last ruby miner.

And then we heard the magic words: Bpai Khao-Duan Chumpon. This was the last ruby mine in Thailand. 'Where?' we asked. 'Oh, you can't go there,' they said. 'Antarai' (dangerous). 'Where?' we asked again. 'Thirty minutes from town,' we were told, with an arm extended in the general direction of Cambodia. And so we set off, to go exactly there, to find the last ruby mine in Thailand. Richard Hughes, Death of the Thai Ruby, 1996


One may be the loneliest number, but thirteen is something else again. In most buildings, 13 is so cursed they skip that floor and, perhaps not coincidentally, childhood dies at that age. Roll the dice and you never hit 13. It's a fact.

Thirteen years ago I set out with my wife and young daughter to find Thailand's last remaining ruby mine:

…I set off for Bo Rai, king of the Thai ruby mining towns. The scene that awaited was devastating. Abandoned equipment littered the landscape everywhere one looked; this once-bustling town showed the early signs of derelict ghost towns from the American West. Hundreds of traders once turned up daily for the early morning rough ruby market. These days, barely five offer their wares. King Ruby Town has quietly metamorphosed into Ban Boredom.

But surely miners must still be going to Cambodia? No, I was told, the Cambodian trade had ground almost to a complete halt. Two reasons were offered: first, the Thai military had sealed the border. Sure, I'd heard that before (nudge, nudge, wink, wink). But secondly, even the Cambodian side was said to have been mined out. I inquired as to the Khmer Rouge, such a ubiquitous presence on the Thai side of the border in years' past. "They're still here," he told me, "all along the base of these mountains." Some things never change.

But will time last forever?

Not taking no for an answer, I drove down one of the old mining tracks that leads into Cambodia. Past the markets, past the semi-markets, past the villages, past the semi-villages, past even the Thai signs warning that this was a restricted area and all civilians should keep out. Still I drove on. Finally, against the mountain that formed the border with Cambodia I saw signs of life. Certainly this must be it – ruby miners heading to Cambodia. Pick-ups and motorcycles parked near a trail. My family and I de-carred and asked where the ruby mines were, only to be led to a waterfall, a pitiful waterfall, at that. We had only succeeded in discovering the local tourist site. The infamous Thai/Cambodian border at Bo Rai, where prospectors once risked life and limb in search of the red stone, had become a two-bit tourist attraction for bored residents of local villages. Bummer.

But we would not be denied. Back in Bo Rai, we asked local merchants – where did the stones in the market come from? And then we heard the magic words: Bpai Khao-Duan Chumpon. This was the last ruby mine in Thailand.

"Where?" we asked. "Oh, you can't go there," they said. "Antarai" (dangerous). "Where?" we asked again. "Thirty minutes from town"' we were told, with an arm extended in the general direction of Cambodia. And so we set off, to go exactly there, to find the last existing ruby mine in Thailand.

Heading north out of Bo Rai for several kilometers, we then turned onto a dirt track in the general direction of Cambodia. Despite the warnings from those who we stopped to ask directions from, all was smooth sailing, until….

Bounding over a hill, we came across a sight which always means trouble, a military border post, manned by the black uniformed troops of Thailand's special forces. Pretending ignorance, I drove past, but the soldier's frantic waving (along with his M-16) convinced us to halt. And thus came the inevitable interview, one which I had endured in so many borderlands throughout Southeast Asia. They seldom proved fruitful.

The commander politely explained that we had run amuck, wandering where we ought not to be. We inquired about mining in the area. Surprise, surprise, we were told that there was no mining along this road. When we explained that those in town had told us that otherwise, and that we had seen a pickup full of miners coming down the road, he admitted that there was some mining, but that they try to discourage it.

"What can we do, arrest them all? They have no other employment." Nods all around, as we reluctantly made our departure, back from whence we had come. A photo op with the commander was politely, but firmly, refused, despite my protestations that I was not working for the CIA. Of course I knew it was not the CIA that he was worried about. His nightmare was a nosy reporter getting into the area he was responsible for and writing that Khmer Rouge troops were there under Thai jurisdiction. But that is another story, for another day….

And so it was, that Thailand's last remaining ruby mine eluded us. As Martin Sheen said in Apocalypse Now, "Never get off the boat." Damn right.

– Richard Hughes, Death of the Thai Ruby, 1996

We rolled the dice, but no thirteen. It's a fact.

The best-laid plans…

Thirteen years had flown by since I wrote those words. By now, everyone knew. The Thai ruby was dead. Gone. All gone. And yet, for some perverse, reason, I still held out hope, that somewhere, perhaps deep in the jungle, a few souls might still be practicing this ancient craft. Call me a luddite. But this was my fantasy.

2001 and 2004 saw me visiting Cambodia's Pailin mines. By the second visit, it was clear that even the Cambodian side was almost completely worked out. 2008 found me back in Thailand.

That November, I journeyed to one of Cambodia's last remaining ruby mines, in Samlot district. The small deposit at Phum O Dat was being worked by a South Korean company. While just a couple hours walk from the Thai border (opposite Bo Rai), it took over 12 hours driving to and from Pailin.

February 2009 saw a further visit to Pailin with my travel buddy, Vincent Pardieu. Vince, now employed as the GIA's Field Gemologist, was undertaking a survey of the world's corundum deposits as part of a gemological Manhattan Project to fully understand these important gems. No one alive has visited as many ruby and sapphire mines as Vince. And yet on the way back to Thailand from Pailin, I realized this poor boy had so much dew around his ears that he’d never actually witnessed a ruby being mined in Thailand.

So we laid plans to change that. We decided then and there to trace the Thai ruby back to its nest. I was pleased. I had found a fellow luddite.

Map of Chanthaburi and Trat, showing the position of the gem mines

Map of Chanthaburi, Trat and western Cambodia, showing the location of the gem mines. Click on the map for a larger view. Map by Maneekan Sahachat/

Several weeks later found Vince and I back in Chanthaburi (จันทบุรี; 'literally 'Moontown'). That afternoon I took Vince on a brief tour of the sapphire mines near Chanthaburi, including Bang Kha Cha and Khao Ploi Waen. Just before sunset we ascended Khao Ploi Waen (เขาพลอยแหวน; ‘Hill of Gems’), where I pointed out the local geography. On one side was the Gulf of Thailand and the flat alluvial plains of Bang Kha Cha. On the other lay Chanthaburi town, with Khao Sa Bap (Sa Bap Mountain) brooding further in the distance. I pointed at the peak and said our destination the following day would be on the other side of the mountain, the dark side. We would be hunting Siamese taub tim—ruby—a name derived from the resemblance of ruby to the seeds of the pomegranite (passion) fruit.

One of the last remaining sapphire miners at Khao Ploi Waen examines a find

One of the last remaining sapphire miners at Khao Ploi Waen examines a find. Photo: Richard W. Hughes, February 2009.

A Visit with the Khmer Rouge (ca. 1983)

Both Bo Rai and Nong Bon lie less than 10 km from the Cambodian border and ruby deposits lie on both sides of the line. Due to nearby fighting between the Khmer Rouge and Cambodian army, shelling is often audible.

At times, thousands of miners have made the daily journey across the border to mine, since the Cambodian side has not been as heavily worked. This is not without its danger. Roving bandit gangs take a steady toll of miners, and those not killed outright may be seriously injured by land mines and booby traps. Were this not enough, the area’s thick jungle is home to some of the world’s worst malaria.

In the mid-1980s, the author and friends decided to explore the border area near Bo Rai more closely. Suitably equipped with jeep, map and camera, we bounced down a muddy path that was a known mining artery into Cambodia. After a few minutes, passing many miners trekking to Cambodia, we rounded a corner, only to find a bamboo pole blocking our way. Familiar with the geography of the area, we realized that we were still well inside Thailand; thus it was a shock to see a teenage soldier in green uniform, a red star firmly affixed atop his hat, Chinese AK-47 in hand. As we approached, in halting Thai he told us to wait and quickly returned with a Thai plainclothes political officer from the military camp located just out of sight. We explained we were researching gem mining in the area, but he politely stressed that it would be best if we went back from whence we had come. Which we did.

Later the same afternoon, possessing the bravado possible only of those who have yet to experience war at close range, we made a further foray to the camp. The same Khmer Rouge guerrilla was present at the barrier, but he now returned with a different Thai political officer. We again started to explain our purpose, but were cut off in mid-sentence: “I know why you’re here. Go back. There is no mining.” “What about all the people walking up the road with pick and shovel?” we asked, but were told in no uncertain terms that there was no mining in the area. As we pondered this, several miners emerged from the jungle path just behind us. “What about them?” we inquired. Casting a cynical glance in the direction of the miners, the Thai officer said “I don’t see anything. Neither did you. Get lost.”

– From Ruby & Sapphire (1997)
by Richard W. Hughes

Dark side of the moon

We set out early on Saturday, hiring a local songtao (taxi truck). Our first stop was Bo Waen (aka Bo Welu; บ่อเวฬ). In former times this was a major source of the Siamese ruby. But that fruit was long gone. Now, like all the rest of Thailand's ruby mines, it was only producing the edible variety. Jack fruit, durian, rambutan and a plethora of other mouth-watering delicacies. Great for the taste buds, but the passion fruit was no more.

Stopping in the market we made inquiries. Anybody got any ruby? No. Nothing, not even a few small pieces of rough? Brows furrowed, discussions were had and then, in a pattern that was to repeat itself over and over, somebody hopped on a motorbike and, minutes later, returned with a bottle, box, vessel or parcel of stones. All dated from a decade or more. There were no fresh kills.

Still, we bought what we could find. When it comes to extinct game, even bones, horns and hides are of interest.

Moving on from Bo Waen, we visited Tok Phrom and then I Rem. Stopping in the local general store at I Rem, I mentioned that, decades before I had purchased nice sapphire crystals in this very spot. The shop owner brought out one nice specimen and said there used to be many, but this was the last piece he had. Showing why Thailand is beloved by travelers from around the world, he presented it to me free of charge.

From here we moved on to Na Wong, where several large parcels were purchased, including a large jug of ruby rough that came with the container (the jug may have been more valuable than the rough!).

Late afternoon found us in Nong Bon. Next to Bo Rai, Nong Bon was Thailand's biggest ruby producer and at one time thousands of miners worked this area. Now there was nothing. We were scraping rock bottom. One old parcel we looked at even had heated rough from Mong Hsu (Burma) mixed with it. This underscores the importance of not just visiting mining areas to collect specimens of known origin, but actually collecting them as they come out of the ground (for more on this, see 'Introduction to GIA’s Sample Collecting Protocol's in Annex 1 of this paper).

At the end of the day, all we had to show were tracks and traces. There were no fresh kills. As the sun set on Nong Bon, we resolved to return again, to visit Bo Rai and explore some of the lesser-known trails that led up to the Cambodian border, in hopes of sighting this most rare of birds, the Thai ruby miner.

April in Moontown

It was now April. We rose early, setting off for Khao Ploi Waen and Bang Ka Cha, to investigate a few new sapphire mines we had discovered during our previous trip. Despite Google Earth, despite the best of connections and intelligence, if there is one thing I’ve learned in thirty years of gem hunting, it is that you must find the source yourself. Go to a place like Chanthaburi and ask about mining in an area just 15 minutes’ drive from town and 99.9% of the gem dealers/brokers/experts you speak with will be completely clueless. There are few real moonwalkers in moontown.

So we set out, driving up and down the tiny lanes that spread out like tendrils from Khao Ploi Waen. With ears cocked for the telltale sound of a bulldozer or water pump we probed the plantations surrounding Chanthaburi's Hill of Gems. Within an hour we had found three previously unknown mines.

Road sign in Bo Rai

Speed rules in Bo Rai. Photo: Richard W. Hughes, April 2009.

But it was a far rarer bird that had brought us to this land, one that would require traveling East. After a two-hour drive, we alighted in Bo Rai, former center of the Thai ruby universe.

The routine was by now familiar. We made our way to the market, hoping to find someone who had lived in the town for many years, someone who may actually remember the nesting places of this now rare bird. A few conversations later brought us nothing. Yes, the people knew that ruby was once mined here, a few had even participated in the business. But it was all gone.

Finally, I mentioned that years' before, I had attempted to go to a place called Bpai Khao (ป้ายขาว)-Duan Chumpun. As I pointed in that general direction, I asked him if he knew of it.

His eyes showed a glint of recognition. Pronouncing it a few more times brought a general nod of approval. He said they were two different places. Yes, he had heard of Bpai Khao, yes, they had rubies there, yes, there might even still be some mining.

And so it was that we set off for Bpai Khao. We were off to find the unicorn, the dodo bird — we were hunting the last Thai ruby miner.

Border trouble

Many twists and turns later, we hit an army checkpoint, the same one that had thwarted my family and I so many years before. This time, they waved us through.

We drove on. Several km and numerous inquiries ahead lay yet another Thai army checkpost. This time they questioned us, but we managed to deflect the inquiries to the degree that we were allowed to continue. Still on the boat.

By now rubber and fruit plantations had disappeared, replaced by a slender piece of concrete squeezed in on both sides by a different kind of green. The flat orchards had morphed into jungle-clad mountains.

At yet a third Thai military post, the questioning was more persistent. Where were we going? Bpai Khao. What were we doing? Looking for ruby. How had we made it past the previous two checkpoints?

Long ago I learned the stupid smile sometimes beats even a straight flush. We grinned, nodded, shrugged and grinned some more. As we grinned we mentioned that we were teachers and students doing a bit of field work, looking for samples of ruby. That got us back on the road with a wave of the hand. Like everyone else in the area, the black shirts knew only too well that our prey had been extinct for over a decade. Silly farangs.

Now the road narrowed considerably as dark storm clouds and the jungle pressed in. Soon the trace ascended straight into the mountains as ominous red skull-and-crossbones signs were posted on either side of the road. From our many visits to Cambodia, we were all too familiar with these postings, which indicated land mines. Only the foolish or the truly desperate failed to heed this warning.

Philippe Ressigeac near the Thai-Cambodian border at Ban Mamuang in Thailand's Trat province Philippe Ressigeac near the Thai-Cambodian border at Ban Mamuang in Thailand's Trat province. Land mines lie on both sides of the road, remnants from the days of the Vietnamese-Khmer Rouge war.

Philippe Ressigeac near the Thai-Cambodian border at Ban Mamuang (บ้านมะม่วง) in Thailand's Trat province. Land mines lie on both sides of the road, remnants from the days of the Vietnamese-Khmer Rouge war. Photo: Richard W. Hughes, April 2009.

As we drove up and up, we encountered the latter. Ascending a hill, we came across a man with a wooden leg and macheté. Stopping to talk, we learned that he was a former ruby miner-turned-bamboo cutter who had lost his leg 100m down the hill several years prior while cutting bamboo in the forest.

We asked about rubies. He said they were all gone.

By now, the track was too steep for our songtao. The woodcutter said the Thai-Cambodian border was just a kilometer away, at the top of the hill. So we walked.

After a brief but sweaty ascent, we crested a ridge and found ourselves at the Ban Mamuang border post. The friendly Thai soldiers invited our tired party up to their abode for cold refreshments and a chat. We took the opportunity to ask about rubies. They said, sure, there's still mining, but not much. Ask the woodcutter where. A few minutes later, we descended again, empty handed.

The wooden leg of a former miner-turned bamboo cutter who had gotten off the boat near the Cambodian border

Antalai. The wooden leg of a former miner-turned bamboo cutter who had gotten off the boat near the Cambodian border. Photo © Richard W. Hughes, April 2009.

By now, the woodcutter had been joined by several others, who were enjoying a meal in the middle of the road. Again, we asked about rubies. To a person, they said they were all gone, that they no longer dug for ruby, it was easier to make a living cutting bamboo.

We asked about Bpai Khao. They pointed off to the mountains to the northwest. We would have to go back down from where we had come. We had missed the turn. But they said there was no mining there. There was no mining anywhere. The rubies were gone. All gone.

And so it was that again, thirteen years later, that we had thrown snake eyes. No Bpai Khao, no ruby mining. The Thai ruby was well and truly dead.

The Thai-Cambodian border at Ban Mamuang in Thailand's Trat province.

The Thai-Cambodian border at Ban Mamuang in Thailand's Trat province. Photo: Richard W. Hughes, April 2009.


Retracing our steps, we again came to the Thai military check post. This time the welcome mat was noticably missing and no amount of grinning would roll it back out. As our truck approached, the officer who had previously questioned us was noticably miffed. Waving at us to stop, he immediately started screaming at our driver. Why had we not informed him that we had not been officially cleared at the previous checkpoint (when the question had previously come up, we had simply nodded and grinned). What were we really doing up there on the mountain?

With his revolver unholstered, he ordered us out of the truck and then began searching all of our luggage while muttering the Thai equivalent of "Field gemologists my ass. I know ya ba (amphetamine) smugglers when I see them!"

What to do? We grinned. Nodded and grinned as he riffled through our belongings, checked the glovebox and even pounded the truck's tires. Alas, there was no ya ba. Just a bunch of clothes and a mound of GIA Gem Fest fliers for a talk I was scheduled to deliver later that month.

Following a bit more grilling, he snorted that we could go. As we climbed back in the truck, he mentioned with a wink that he had to be careful, that Thailand's fugitive ex-prime minister, Thaksin Shinawatra, was "out there somewhere." I briefly thought about asking why he checked the glovebox, but in the end, just grinned. Nodded and grinned as we drove away, back towards Bo Rai. Back on the boat. Damn straight!

A few minutes further on and I thought, jeez, this is my second go at this. Now we're so close. Even if there is no more mining, we might as well see the place. Fortunately, I was traveling on a ship of similar fools, silly farangs, luddites. My fellow imates needed no coaxing. They quickly agreed. Upriver we went. . .

We came to a group of people at a creek and asked directions to Bpai Khao. They pointed off towards cloud-draped mountains in the distance, but said there was no more mining. It was gone. All gone. As we drove off in that direction, I could just hear them saying to themselves: "farang ba (silly farangs)."

Mutiny on the good ship Farang Ba

A few kilometers of dirt track brought us to a small house. We knew the drill. Stop, ask directions, ask about ruby. Bpai Khao? Yes, this was the road. Rubies? No, no more mining. The rubies were gone, all gone.

Another klick brought us to a house and a small creek filled with a few cm of water. Our driver took this opportunity to mutiny, protesting that his truck could never make it across. Why, we asked? Brakes, the water will ruin the brakes, we were told. After a brief negotiation, alongside a promise to buy him a new truck if we suffered brake-shoe failure, we set out to cross the Mekong. Three seconds later, we were back on the boat, Bpai Khao or bust.

Who cares?

Field work is not always fun. Long periods of boredom, broken by moments of discomfort, fear and anguish. And yet we continue to travel to some of the most gawd-awful places. Why? The best answer is that because if you travel enough, eventually you hit bottom and start up again. On those rare occasions when you reach the nadir, every kilometer further on brings a further revelation. At that moment you realize further on is exactly where you are now and where you always want to be.

I've experienced it a few times in my life; on this trip it came on with a rush. Driving up that valley, the clouds slowly parted and as the sun came out, what had been a dark, depressing experience faded into obscurity. Glistening from the recent rains, the forest took on a glow that slowly morphed into something simply ethereal. True, we had found no rubies. As everyone had said, they were gone. But in the search we luddites had discovered something equally valuable.

We pulled up at the single house that constituted the hamlet of Bpai Khao, knowing there were no more rubies, but at this point didn't really care. We had finally arrived. Bpai Khao. Yes! The sun was shining, it was a beautiful day, we were in Thailand. What more could one ask for?

A group of people were busy loading cashew nuts into a truck; they soon departed, leaving behind two men and a dog. One wore a cap with the slogan "Hard Rock Cafe."

We knew the drill. Any rubies? No, none, all gone, long gone. . . huh?

A hand fished into a pocket and eventually came up for air holding a small plastic bag. As it was raised in front of our eyes, water glistened. We stared in silence. Fresh air, sun shining, all was right in the world on this perfect Thai day. What more could one ask for?

Thirteen years ago, throw the dice—snake eyes. Thirteen years' later, another throw.

Call it what you like. Luck. Joss. Destiny. We had just thrown the impossible thirteen. Inside the bag were several red pebbles. We had found Thailand's last ruby miners.

Thailand's last ruby miner

One of Thailand's last ruby miners with the day's take. Photo © Richard W. Hughes, April 2009.

A handul of rubies, along with a piece of quartz from Thailand's last ruby miner.

A handul of rubies, along with a piece of quartz from Thailand's last ruby miners. Photo © Richard W. Hughes, April 2009.

Implements of a dying breed.

The primitive tools of one of Thailand's last ruby miners. Photo © Richard W. Hughes, April 2009.

Lotus logo


The author would like to thank our driver, Mr. Sang, who has cheerfully ferried us down highways and byways across Chanthaburi and Trat. Also our travel mates, Michael Rogers, Olivier Segur and Philippe Ressigeac. And most especially, to my best friend, Vincent Pardieu, who has helped me in my travels across the world and who will always remain my number one travel buddy. I look forward to many more pleasurable corundum adventures with Vince.

References & further reading

  • Bacon, G.B. (1893) Siam, the Land of the White Elephant, as it was and is. New York, Charles Scribner’s Sons, 296 pp.
  • Berrangé, J.P. and Jobbins, E.A. (1976) The geology, gemmology, mining methods and economic potential of the Pailin ruby and sapphire gem-field, Khmer Republic. Institute of Geological Sciences, Overseas Division, Report No. 35, 32 pp. + maps.
  • Brown, G.F., Buravas, F. et al. (1951) Geological reconnaissance of the mineral deposits of Thailand. Bulletin, US Geological Survey, Vol. 984, 183 pp., 20 pls., 38 figs., 4 tables.
  • Coenraads, R.R., Vichit, P. et al. (1995) An unusual sapphire-zircon-magnetite xenolith from Chanthaburi gem province, Thailand. Mineralogical Magazine, Vol. 59, No. 3, pp. 467–481.
  • Chang-Glom, K. (1988) Chanthaburi. [in Thai]. Sara-Kadee, Bangkok, 235 pp.
  • Gühler, U. (1947) Studies of precious stones in Siam. Siam Science Bulletin, Vol. 4, pp. 1–38.
  • Hoskin, J. (1987) The Siamese Ruby. Bangkok, World Jewels Trade Center, 119 pp.
  • Hughes, R.W. (1997) Ruby & Sapphire. Boulder, CO, RWH Publishing, 512 pp.
  • Hughes, R.W. (1997) Devil's Advocate: Thailand after the fall. Cornerstone, Winter, 1997, pp. 1, 3–6.
  • Hughes, R.W. (1997) Devil's Advocate: Life during wartime. Asia Diamonds, Vol. 1, No. 2, Sept-Oct, pp. 68–72.
  • Hughes, R.W. (2009) History of Chanthaburi.
  • Hughes, R.W. (2009) Red and blue: Chasing history in Chanthaburi & Trat.
  • Hughes, R.W. (2009) Rhapsody in blue: A Pailin photo gallery.
  • Jobbins, E.A. and Berrangé, J.P. (1981) The Pailin ruby and sapphire gemfield, Cambodia. Journal of Gemmology, Vol. 17, No. 8, Oct., pp. 555–567.
  • Keller, P.C. (1982) The Chanthaburi-Trat gem field, Thailand. Gems & Gemology, Vol. 18, No. 4, Winter, pp. 186–196.
  • Loubère, S., De la (1693) A New Historical Relation of the Kingdom of Siam. London, reprinted by White Lotus, Bangkok, 1986, 286 pp.
  • Louis, H. (1894) The ruby and sapphire deposits of Moung Klung, Siam. Mineralogical Magazine, Vol. 10, No. 48, pp. 267–272.
  • Ma Huan (1970) Ying-Yai Sheng-Lan ‘The overall survey of the ocean’s shores’ [1433]. Cambridge, Hakluyt Society, Extra Series, No. 42, 393 pp.
  • Pallegoix, M. (1854) Description du Royaume Thai ou Siam. Paris, see pp. 117–121.
  • Pardieu, V. (2009) Pailin, Cambodia (Dec. 2008–Feb. 2009). Concise Field Report, Volume 1, GIA Laboratory, Bangkok,
  • Phillips, G. (1887) The seaports of India and Ceylon [Ma Huan’s account of Ceylon and the Kingdom of Siam (Hsien-lo-Kwo), 1408]. Journal of the Royal Asiatic Society, China Branch, Vol. 20–21, pp. 209–226; 30–42.
  • Smyth, H.W. (1895) Notes on the Geography of the Upper Mekong. Brisbane, Australian Association for the Advancement of Science, pp. 533–551.
  • Smyth, H.W. (1895) Notes of a Journey on the Upper Mekong, Siam. London, Royal Geographical Society, reprinted 1998 by White Lotus, Bangkok as: Exploring for Gemstones on the Upper Mekong, 109 pp.
  • Smyth, H.W. (1898) Five Years in Siam—From 1891 to 1896. New York, Scribner’s, 2 Vols., Reprinted 1994, White Lotus, Bangkok, 330, 337 pp.
  • Smyth, H.W. (1926) Sea-Wake and Jungle Trail. New York, Frederick A. Stokes, 323 pp.
  • Smyth, H.W. (1934) Chase and Chance in Indo-China. London, Blackwood, 379 pp.
  • Taylor, G.C., Buravas, S. et al. (1951) Geologic reconnaissance of the mineral deposits of Thailand. USGS Bulletin, No. 984, pp. 144–150.
  • Vichit, P., Vudhichativanich, S. et al. (1978) The distribution and some characteristics of corundum-bearing basalts in Thailand. Journal of the Geological Society of Thailand, Vol. 3, pp. M4–1 to M4–38.
  • Vichit, P. (1992) Gemstones in Thailand. Dept. of Mineral Resources, Bangkok, Thailand, Piancharoen, C., ed., In Proceedings of a National Conference on Geologic Resources of Thailand: Potential for Future Development, Bangkok, Supplementary Volume, pp. 124–150.

About the authors

Richard W. Hughes is the author of the classic Ruby & Sapphire and over 170 articles on various aspects of gemology. Many of his writings can be found at and His latest book is Ruby & Sapphire: A Collector's Guide (2014).

Vincent Pardieu is Field Gemologist at the GIA Laboratory, Bangkok. His writings and research can be found at and at

Michael Rogers is a budding gemologist from Hawaii, who was a part of the insane gem posse's 2007 trip to Kenya and Tanzania.

At the time of writing, Olivier Segur and Philippe Ressigeac were gemology students in Bangkok. As of 2014, Olivier is now director of France's Laboratoire Francais de Gemmologie, while Philippe is working for Gemfields at their Montepuez ruby mine.

Back to top