Thailand Unearthed: Uncovering gemstone wholesalers who sell to the wholsalers in Chanthaburi

Located in Thailand's southeast, Chantaburi is a provincial town with global reach. Known for its enduring role in the sapphire trade and other coloured gemstones, it remains one of the most important coloured gemstone centres in the world. What once began as a mining town is now a global crossroads. The city blends local tradition with international commerce, serving as both processing centre and marketplace. Sapphire mining near the city of Chantaburi is now limited, but remnants of activity still remain. Here, black star sapphires and party coloured sapphires are still recovered using small-scale techniques passed down through generations. Most of Thailand's gem material is now imported, yet these deposits still hold cultural significance. So this is a typical small-scale mine here in Thailand. They're looking for black star sapphire, they might find the occasional party sapphire as well if they're lucky. Essentially it's the same type of mining we've seen all around the world when it comes to small scale. We've got all the rubble up there, all the gravel that's being washed down into the pulsator there, it gets bounced around, all the heavy stuff comes out, like the sapphires hopefully will get trapped in the pulsator, while everything else is just going to be washed away due to its lighter density or its less density. At the end they're going to turn off the pump, that's all going to come to a stop and we'll take out the top of the gravel and hopefully we should find some sapphires inside if we're very lucky. All right, now he's giving me a go on the hose here. Not sure how I'm going to do it but we'll see how we go, right? Chantaburi sapphires lie in loose gem-bearing soils formed by the tropical weathering of ancient basalt flows. These volcanic rocks, dating back around 1.4 to 2 million years, brought sapphires to the surface as they erupted. Over time, rain and erosion wore down the basalts, leaving their heavier corundum crystals concentrated in alluvial deposits. Today, miners recover these sapphires from shallow layers of soil. Each stone a testament to the area's volcanic past and the region's inactivity since. So we're just going through the first rib of the pulsator here. Basically, as we've said before, this is always going to be where most of the stones are ending up because the heavier stones will get trapped here, so I think just for this trip we'll just look for the first one. We found a couple of black spinels maybe, black tourmaline, unidentified black amphiboles shall we say, and there's not much left there but we'll see how we go. Will you find some glowing sapphire? I wish. Chantaburi has pioneered global techniques for heat treating ruby and sapphire in recent history. Through controlled heating, color and clarity can be permanently enhanced. Since coming to prominence in the 1970s, Thailand has become the main center for the heat treatment of colored gemstones. This is the typical factory and here they'll heat many gemstones like corundum. Here's a typical Thai furnace for using to heat sapphires. The temperature normally will be around 800 to 900 Celsius degree but it can go up to 1400 Celsius degree as well. By reaching this temperature, they are using the mixture of oxygen and the LPG gas. In this heating factory, normally they heat the blue sapphires. They put the blue sapphires inside a sealed crucible and then they put in the furnace. It will heat around for one hour time and then they take out for cooling around 30 minutes and then they will check if the color gets improved a lot. If it's not improved enough they have to put back in the furnace and reheat again and this whole process can take up to 24 hours. So sometimes they also heat treat ruby here. You can see they've got some very fine grain material here. All very small pieces but they're filling up all these little containers. We're not entirely sure why they're doing it like this. He was filling up a crucible before and putting into these containers but they have a secret facility just maybe 20 meters that way where they actually do the treatment but we can't actually get access to that unfortunately because that is a secret and in this sort of trade it is quite a lucrative thing so you don't want to be giving away those secrets so we won't push them on that but it is very interesting to see them treating ruby here. The cutting industry in Chanterbury is also a major part of the industry. Cutting in Chanterbury often focuses on a mix of commercial calibration, stones cut to standard dimensions for the global jewelry trade and free size pieces for those one-off jewels. The skills here are practical, efficient and responsive to demand. Large-scale commercialization and traditional handwork coexist. The weekend gem market attracts traders from across Thailand and around the world. You will find only a handful of traditional style market stalls. Instead transactions happen on sidewalks, in private offices and inside open plan trading areas built to facilitate the organized chaos of gem commerce. Dealers arrive with lists of their stones on display and sit with dozens of sellers in rapid succession. So if things get too hot for you outside you can come into one of the air-conditioned offices. In the Chan Gem building here this is kind of the epic version of all that. You can see this is one massive area where we've got all the tables set out here. It's about five stories apart with all the natural light coming in which is super important for color gemstones and basically you just sit down and you grab one of these tables and you just start buying. So we're going to see Here in Chan Gem's building we found our table. Normally you have to pay 700 baht for per day so you can sit here and buy gemstones. And Janabree is a pre-wholesale market because most of the rough gemstones they will enter into Janabree market first. Here they will finish all the cutting and heat treating in all the factories. After finish all the process they will send to the Janabree market to sell here. Most of the gemstone dealers in Bangkok they will come here to buy the gemstones during the weekends and so they can bring to Bangkok to sell to their wholesale customers in Bangkok. The Janabree market normally open from Friday to Sunday, three days. For a more retail oriented experience Chanterbury also has an ample amount of bricks and mortar storefronts. For visitors gem shops provide access to rough polished and set gemstones and a variety of interesting minerals. While these stores play a minor role in the global supply chains they form part of the town's identity, catering to tourists and gemstone enthusiasts drawn to Chanterbury's gem hub reputation. Gemstones may pass quickly through this town but the knowledge and expertise that transforms them resides here permanently. Chanterbury's artisans, traders and treaters maintain a delicate balance between secrecy and skill sharing, an ecosystem built not only on stones but on trust. Over the years Chanterbury's role has shifted from miner to modifier to market maker. Most stones seen here today originate abroad yet their final polish, colour and commercial identity are shaped locally. In the world of coloured stones Chanterbury remains both a destination and a transformation point, a quiet power in the global gem trade. Smells so good, I like it.