Sapphire is the birthstone for September, and the gem of the 45th wedding anniversary. They are usually a deep, beautiful blue, but natural “fancy” sapphires also occur in yellow, purple, orange, and green colours; “parti sapphires” show two or more colours.
There are also star sapphires, opaque gems with a star like appearance. The stones are cut en cabochon, and heat treated. The character Brick owns a pair of star sapphire cufflinks in Tennessee Williams play “Cat on a Hot Tin Roof”.
Qualities of Sapphire
Sapphire is formed from low silica, coarse grained igneous rocks. Magma cools slowly, allowing the minerals to grow. The natural sapphires are often mined in Kashmir, Burma and Sri Lanka.
The gems were discovered very early, and were referenced in historical texts. They are often heated to enhance their natural qualities – a practice dating back to at least Roman times.
How Sapphire is Used
Most sapphire crystals are cut and polished into gems and used in jewellery. It is the third hardest mineral, making it useful for many commercial applications. To meet demand, synthetic gems are made in labs for use in the technical industries. It has military use, in shatter resistant windows and body armour. Sapphire crystal output windows are used in some xenon arc lamps.
It is also incorporated into optical components, watches, and electronic wafers.
Symbolism of Sapphires
To some religions, the blue colour of the sapphire represents the heavens. The Persians believed it symbolised the sky.
Kings wore the stones around their necks as a powerful defence from harm. They preserved the wearer from envy and attracted divine favour. They have a long association with the British Royal Family.
The Ancient Greeks associated sapphires with Apollo. Worshippers often wore the gem while consulting oracles, such as the one at Delphi. Necromancers sought the stone for their supposed ability to control spirits.
Famous Sapphires
- The Bismarck Sapphire Necklace. It is a Burmese stone set into a necklace designed by Cartier in 1935.
- The Black Star of Queensland. This is a rare 733-carat black star sapphire found in the mid 1930s by 12-year-old Roy Spencer. It was reputed to bring its owners luck.
- The Logan Sapphire is a flawless Sri Lankan gem, set in a diamond brooch. It lives in the Smithsonian Museum.
- The Star of Adam is the largest star sapphire in the world; at 1,404.49 carats. It has been valued at over $300 million.
- The Stuart Sapphire is part of the British Crown Jewels. It has been handed down over centuries, with sojourns in Italy and with the Papacy.