with oil), heating, heating with a flux, heating with lead glass filling (rather rare), and diffusion treatment.

These treatments include fissure filling (e.g. Sapphires are quite often treated to improve their appearance. Many sapphires today are treated to enhance their colour or transparency, and synthetic sapphires are also present on the market. Some of the most famous and expensive sapphires in the world come from Kashmir (India), though the mines there have not been active in recent decades. Main producing countries include Sri Lanka, Burma, Madagascar, Australia, Vietnam, Tanzania, Nigeria, Laos and Thailand. Sapphires form either in metamorphic environments or in magmatic (basaltic) deposits. Padparadscha sapphire is a variety of corundum from any geographical origin whose colour is a subtle mixture of pinkish orange to orangey pink with pastel tones and low to medium saturations. bluish grey, greenish yellow, reddish pink). yellow sapphire, orange sapphire, pink sapphire, and purple sapphire to name a few, or by the generic term ‘fancy sapphire’ for further fancy colours (e.g. All other colour varieties of corundum are either described by using a colour prefix, e.g. The term sapphire without a colour prefix is reserved only for the blue variety of corundum, coloured by iron and titanium.

Royal blue sapphire