With a hardness of 9 on the Mohs scale, rubies are made up of corundum, the second hardest natural material known to man. Red gem-quality corundum is traded as natural ruby, while all other colors are traded as sapphire. The name 'corundum' was derived from the ancient Sanskrit word 'kuruvindam'. Ruby is sourced from many regions of the world, including Afghanistan, Australia, Brazil, India, Cambodia, Kenya, Thailand, Myanmar (Burma), Sri Lanka (Ceylon), Tanzania, Malawi, Mozambique, Nepal, Pakistan, Zimbabwe, Tajikistan, the USA, Vietnam and Madagascar. Madagascar is one of the newer sources for ruby gemstones.
Madagascar is located approximately 400 km off the coast of Southeast Africa, and as of recent times, it has become one of the most important sources for fine-quality colored gemstones , particularly ruby and sapphire. Historically, Madagascar's economy was fueled by agriculture, but around the early 1990s, gemstone mining began to become commercialized. Shortly after in 1998, an enormous sapphire deposit was discovered in the tiny village of Ilakaka, which came as a complete surprise and led to a gemstone-fever reminiscent of the mid-19th century gold rush in California.
In fact, Madagascar is believed to have some of the richest untapped gemstone reserves in the world. The two important ruby deposits of Madagascar are located in the eastern regions of Vatomandry and Andilamena. The first rubies from Andilamena were discovered in October of 2000, but they were not well-received by the general public owed to the poor quality of material, which lacked transparency and most were rather dark.
In January 2001, better quality rubies were discovered and weeks later, there were nearly 40,000 miners actively working in the Andilamena area. Rubies from this region were found in well-formed tabular crystals with slightly rounded edges, averaging around 2-3 carats each. In addition to fine ruby and sapphire, a large variety of other gemstone types have been discovered in Madagascar, including fine tourmaline, aquamarine, emerald, garnet, chrysoberyl, alexandrite, topaz, andalusite, apatite, kyanite, zircon, amethyst and citrine.