METHODS used by gem cutters have hardly changed in hundreds of years, but in Myanmar, the development of the gem industry means there are now more companies exporting expertly cut gems out of the country.

»Workers at a gem factory in Yangon polish precious stones to bring out their beautiful colour and lustre.

The lapidary (someone who is skilled in cutting and polishing jewels and valuable stones) has become all-important because the quality – and value – of a gem is determined by the cut.

Daw Kyu Kyu Hlaing, the owner of the Mir and Alpha Gem and Villia Gem Cutting Factory, has been in the gem cutting industry since 1995 when she inherited the business from her mother, also a lapidary.

“We used to cut gems by hand, but now we use a gem cutting machine that was bought in Bangkok,” she said. “The machines were invented by a Myanmar man called U Saing Maung Kun in 1980.”

Like many gem cutters, Daw Kyu Kyu Hlaing keeps her cutting methods secret from other lapidaries. But she has trained 40 gem cutters who now work at her factory.

“There are two steps in gem cutting: First a rough cut is made before the second, which is the final cut,” she explains.

“We used to use sapphire powder to polish the gems but now we use diamond powder, which gives the diamonds beautiful colour, and hopefully a high price,” Daw Kyu Kyu Hlaing said.

Mr James Firmin, a leading gem trader from London, agrees that gem cutting has become a more refined art.

“Cutting in the past was less accurate . . . mainly due to less advanced equipment. Often the cutters would merely polish the faces of the gem crystal, rather than making a predetermined shape like a diamond cut,” he said.

The cutters would use a lap (circular polishing wheel) coated with diamond or sapphire powder, if available, which would usually be turned through the use of a foot pedal. A primitive example can still be seen in use in Sri Lanka today, in the form of a stick attached to the wheel axis by a rope.

“On a modern machine, the stone is held by a ‘dop’ (the part of the machine that holds the gem), which is turned for accurate symmetry,” Mr Firmin said.
“The angle of cutting is important to ensure the gem sparkles; each mineral has its own specific angle. For example, a diamond must be kept shallower then an amethyst. Some stones – especially rubies and sapphires – must be cut in the correct direction of the crystal since the colour changes with the direction.”

Gems should be cut in a way that empasises their qualities, said U Kyaw Thu, the assistant production manager at Myanmar VES Joint Venture Company Ltd, “which include colour, lustre and fire.”

“To cut a stone, we need a tougher material. . . . For instance, to cut a diamond you need another diamond as it’s the hardest stone,” he said.

There are two styles of cutting: A ‘cabochon’ cut is the oldest form of cutting in which the stone is smoothly rounded; while the faceted cut, which produces symmetrical plain surfaces on the gem, is a popular method for cutting diamonds.

“The most common cut is the brilliant. In addition to the round brilliant, stones are cut in a variety of square, triangular, diamond-shaped, and trapezoidal faceted cuts. The use of such cuts is largely determined by the original shape of the stone,” U Kyaw Thu said.