Common characteristics in rubies produced in Mozambique are:
While Thailand is more historically associated with these types of characteristics, since both sources are basalt-hosted (meaning high iron, darker rubies) they are capable of producing similar stones in appearance, inclusions, and chemistry. The Mozambique rubies are also the most widely available of the high-iron rubies.
R7052 | medium | play | “Ruby ID:R7052”
Rubies have been detected in the region as far back as the 1500s, but there was no mining until after Mozambique’s independence from the Portuguese in 1975, then the ensuing civil war, and flooding. Mining actually started in the 1990s, and did not start resembling current output until around 2010.
In 2011, one of Mozambique’s largest mining companies partnered with the British company Gemfields to establish the Montepuez Ruby Mining Company. This effort has produced a streamlined mining process with improved infrastructure, machinery, and security. Mozambique is one of, if not the largest ruby suppliers in the world.
As the area sees increasing interest and a flood of rubies being produced, large scale mining operations have come into conflict with the smaller, artisanal miners and mining staff being brought in from dried-up Thai mining sources.
Thailand rubies (also called Pailin rubies) are historically noted to be darker, and can have a slightly orange (scarlet) appearance. Typical features include various combinations of:
Despite being a historical producer of rubies, they do not produce much currently. However, the country remains a major cutting and trading center for rubies. It is also a center for treating lower-quality ruby material.
Like other countries, it had been known that there were rubies in Thailand but mining operations did not begin until relatively recently in 1895. The rights to mine in Siam were granted to a British company called The Sapphires and Rubies of Siam, Ltd. This company was related to The Burma Ruby Mines Ltd., which worked the famous mines of the Mogôk Valley in Burma. The venture was not commercially successful.
When the Siam Mining Act was passed in 1919, gem extraction in the country was reserved for Thai nationals. After the 1960s, heat treatments for the undesirable brown and bluish color zoning in rubies had been improved. When coupled with the declining production in other parts of the world at roughly the same time, Thai rubies accounted for roughly 80% of the world’s ruby supply by the 1980s.
The Thai ruby deposits are now depleted, however the country still remains a major center for cutting, treating, and trading rubies in Bangkok (at the northernmost point of the Gulf of Thailand) and Chanthaburi (Southeast of Bangkok). With lots of ruby mining going on in neighboring countries like Cambodia, and even Mozambique the expert miners and mining companies from Thailand continue to search for rubies.