A rich blue gemstone, the name comes from the Greek word for blue. Sapphire is a variety of the corundum mineral, as is RUBY. Tiny quantities of titanium and iron give rise to the colours of sapphire, which can be yellow, pink, or green, as well as blue. It is a more common gemstone than ruby and today is found mainly in Australia, although exceptional blue and pink sapphires have been extracted from the gem-rich gravels in Sri Lanka for over 2,000 years. Large sapphires are extremely rare; the largest cut star sapphire, the ‘Star of India’, is in the American Museum of Natural History in New York. Two famous sapphires, St Edward's and the Stuart Sapphire, form part of the English Crown Jewels.