All About Rubies

The journey to the world's most important ruby deposits takes us further on to the small town of Mong Hsu in the North-East of Myanmar, where the most important ruby deposits of the nineties lie. Originally, it was believed that these rubies would hardly prove suitable for use in jewellery, since untreated Mong Hsu ruby crystals actually display two colours: a purple to black core and a bright red periphery. Only when it had been discovered that the dark core could be turned into deep red by means of heat treatment did rubies from Mong Hsu begin to find their way on to the jewellery market. Today, the Mong Hsu gemstone mines are still among the most important ruby suppliers. In the main, they offer heat-treated rubies in commercial qualities and sizes between 0.5 and 3 carats.

Ruby deposits also exist in neighbouring Vietnam, near the Chinese border. Rubies of Vietnamese origin generally display a slightly purplish hue. Rubies from Thailand, another classical supplier, however, often have a darker red which tends towards brown. This 'Siamese colour' - an elegantly muted deep red - is considered second in beauty only to the Burmese colour, and is especially popular in the USA. Ceylon rubies, which have now become very rare, are mainly light red, like ripe raspberries.

Other ruby deposits are located in Northern Pakistan in the Hunza Valley, Kashmir, Tadzhikistan, Laos, Nepal, and Afghanistan. But rubies are also produced in India, where deposits with relatively large crystals were discovered in the federal states of Mysore and Orissa. These crystals have many inclusions, but they are, nevertheless, eminently suited to being cut as beads or cabochons.

Lately, people have begun to talk about East Africa as a source of rubies. Straight after their discovery in the 1960s, rubies from Kenya and Tanzania surprised the experts by their beautiful, strong colour, which may vary from light to dark red.

Rubies are the birthstone for the month of July.