Exploring the World's Major Gem Deposits: From Rubies to Sapphires and Beyond
Major Gem Deposits Worldwide.
Ruby
Ruby has been mined extensively over the last four hundred, whilst prior to that, many smaller alluvial deposits have brought these most sought-after stones to the market for millennia. Strangely enough, many old stones found in Royal jewelry from both Asia and Europe are actually spinels, not rubies.
The main source was always Myanmar, however historically, India, Pakistan, Afghanistan, Thailand and Sri Lanka were also very productive sources for rubies of all qualities.
Nowadays, Myanmar only produces a small amount of rough as the main mining areas of Mogok and Mong Shu have primarily been mined out, whilst the pegmatite sources still with production now require very high investment with low returns.
Mozambique is now the main supplier for the world’s gemstone business, with other African countries such as Madagascar, Tanzania, and Malawi also proving popular. Unfortunately, it usually takes at least ten to twenty years for the market to catch up with a new gem source, so the prices for these African stones are still considerably less than their Burmese counterparts, despite the colour and general quality being very similar.
Sapphire
Sapphires have been mined for thousands of years, with Ceylon, or Sri Lanka as its now known, being an early source for gem quality stones. Kashmir blue sapphires have for the last one hundred years been the most sort after and thus most expensive stones, whilst stones from Myanmar and Sri Lanka have actually provided most of the stones for the middle to high-end segment of the jewelry business.
Madagascar, a relatively new source, has been supplying very good quality stones for the last twenty-five years, whilst Montana sapphires were used extensively in the watch business from the nineteenth century. Thailand was a large supplier of stones for about thirty years but most of the remaining areas are now too expensive to mine. Australia is still a major supplier of commercial quality stones, whilst newer sources in Nigeria and Ethiopia are now having an impact on this segment of the market. Other sources such as China, Laos, the Congo, Tanzania, Cameroon, and Malawi continue to provide sporadic supplies.
Major Mining Companies
The largest ruby mining company worldwide is Gemfields, who hold regular auctions of their Mozambique production in Singapore.
 Fura Gems is the second largest ruby mining company worldwide, however, they also have major sapphire mines in Madagascar and Australia. They auction their production in Thailand.
Other large mining companies are operating in Myanmar, Mozambique, Nigeria, and Sri Lanka, however, they are private companies and generally keep a low profile. Some of these companies do occasionally sell through the auction house Bonas, based in Dubai.
