The most popular colour is blue, and some of the worlds largest and most famous Sapphires are also blue. The St Edward's Sapphire is set into the cross at the top of the Imperial Crown (pictured right), part of the Crown Jewels of England. The Star of India is the largest blue Sapphire at 536 carats, and was donated to the American Museum of Natural History...it was stolen in 1964 by infamous jewellery thief (surfer, artist, musician and various other 'occupations') Jack Murphy (Murph the Surf), but recovered two months later from a foot locker in Miami.The Black Star of Queensland is 733 carats, it was discovered by a 14 year old boy in 1935, and used as a doorstop until 1948!!
Sapphires are mined in Thailand, Sri-Lanka, Burma, India, Australia, America, Tanzania, Cambodia and Madagascar, though Burma and Kashmir are now producing very little material.
Most Sapphires are heat treated to improve the colour. Stones are subjected to temperatures between 1700 and 1800 degrees Celsius for several hours. Beryllium can also be added during heating to reduce the blue tones in yellowish stones, making them appear a more brilliant yellow-orange.
To see my range of Sapphire and 925 Sterling Silver jewellery, please click the link below:
http://hollysfriends.co.uk/products/jewellery/birthstones/
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