Gem Mining in Thailand

The rolling hills of Koh Chang’s home province of Trat and the neighbouring province of Chantaburi have a long history of being the source of high quality gemstones, most notably rubies and sapphires. This led to the area developing into a major gem mining and trading centre.

But before you grab a spade and head up to the hills of Koh Chang to make your fortune it is worth noting that Trat’s gem industry is centred on the small town of Bo Rai which is located close to the Cambodian border about 30 km north of Trat Town. Today there is a gem mining museum there that you can visit.

Whilst there is less gem mining these days the gem market in Chantaburi still brings serious gem traders from all over the world. The narrow streets of Chantaburi’s old town are crowded with gem shops and every weekend sees frenzied bargaining, bartering and haggling as precious stones from near and far change hands. Unpolished gems are often brought to Chantaburi from as far away as Africa to be treated by the town’s expert gem polishers.

The rubies and sapphires of the region are found in old river beds, usually at depths of about three to six feet. The mud and soil need to be washed away from the gravel and then this has to be painstakingly hand sorted to reveal the gems, a job of great concentration and expertise.

Rubies and Sapphires are both varieties of a precious stone called corundum, which is chemically a super-hard form of aluminium oxide. The “colour” of a gem depends on trace amounts of other elements found in the stone. The red colouring of rubies is due to the presence of chromium. Sapphires can be a number of colours ranging from pink to green, although the most familiar, colouration is blue. Shades of purple or violet are considered to enhance the beauty of the stone whilst green detracts from a stone’s appearance and value.

Rubies and sapphires along with diamonds and emeralds are considered to be the four genuinely precious stones with all other gemstones being classified as semi-precious.

It takes an expert gemmologist to trade with the professionals of the Chantaburi gem market, although there is of course no harm in visiting and soaking up the atmosphere of this interesting town. Fortunately though there are shops on Koh Chang where you are able to explore and learn about the delights of the region’s precious stones and of course they are available over here at far more reasonable prices than you will find back home.