Hard Diamond

Thailand

I have travelled the world in search of gemstones: both rough cut and polished. I’ve been to northern Rajasthan in India, to Ratnapura in Sri Lanka, and to South America, Madagascar etc. This week I’m in Thailand. I haven’t been for two years, but I am here this year with my partner, Sally, and our 14 month-old baby, Lola (pictured with me here and loving the place and the people). The reason Thailand is my choice is that the cutting of gemstones there has superseded the other countries I have mentioned, and Thailand has become an independent and wealthy country where gemcutters are able to cut gems using the latest cutting edge industrial tool technology. Also, the people of Thailand are a race that are both determined and able to concentrate on detailed things for long periods of time, an ability related to their long, unbroken history of craftsmanship. Lastly, they are some of the friendliest and most honest people I’ve ever met. Many gemmologists I meet in Thailand are from all over the world, and are there for the same gemmological reasons as me.

Diamond intro

Like many a fine jeweller, I have a great respect for and interest in diamonds. As we all know, the diamond is the hardest natural material known to exist on earth. Naturally, the easiest way to test the hardness of a substance is to scratch it with another very hard substance. That’s what a mineralogist called Friedrich Mohs did in the early nineteenth century. Using this method he was able to set up a universal table of hardnesses which is still used today, and is based on the ten most prevalent stones.

The stones are laid out on a 1-10 scale: 10 is the diamond, 9 is ruby or sapphire, 8 is topaz and it goes along to 1 which is simply talc. But to give you an idea of the uniqueness of the diamond, it is not just harder than the others, it is actually 140 times harder than the second-placed sapphire. Incredibly, this means the difference in hardness between the diamond at 10 on the Mohs scale and the sapphire at 9, is actually greater than the difference between the sapphire at 9 and the soft talc at number 1.

So gemologically the diamond is a fascinating stone. Needless to say, the trade in diamonds dwarfs the trade in any other gemstones. For more than 100 years, the diamond trade has been dominated by De Beers Consolidated Mines Ltd. It has a London-based trading arm called the Central Selling Organization, but in the jewellery trade it is commonly referred to as the “The Syndicate”. De Beers controls 85% of the world’s rough diamond trade. By controlling the supply of diamonds to the market, De Beers has for decades protected the value of the diamond. However, it has also broadened the market for diamonds. Once diamonds were the sole preserve of the super rich; but in the twentieth century, to an extent at least, the diamond has become more widely available.

This picture shows a rough diamond of unique size and quality, so the diamond which has been cut from the rough has been cut to the size and shape which the rough best permitted. This cut preserves the flawless quality of the material, and demonstrates the skill and precision of the great diamond cutters.