Sapphire

Sapphire is an aluminum oxide. Its colour varies from very light to dark blue to violetish-blue, bluish-green, yellow, slightly reddish-orange, brown, nearly opaque black, colourless, pink, violet and the pinkish-orange padparadscha (lotus flower).

Varieties
Coloured varieties, star sapphire, alexandrite-like sapphire.

Sources
Sri Lanka, Kashmir (India), Burma, Thailand, Australia, Tanzania, Kenya, Montana, Madagascar

Toughness
Excellent, except in laminated or fractured stones.

Precautions
Sapphires may fade if heated

Treatments
Sapphires can be x-rayed to intensify their colour. Natural sapphires undergo heat and diffusion treatments. With the first method, sapphires with latent chemical components for good colour are “ripened” to a desirable colour through heating. In diffusion treatment, sapphires that lack the components for good colour are placed in a bath of colouring oxides that penetrate the outer layers of the stone.

History
According to an ancient Persian legend, the earth rested on a great sapphire whose reflection was seen in the sky. The stone also appears in the Promethean legend. Prometheus was chained to a rock by Zeus for having stolen fire from the gods. After being rescued by Hercules, a link of the chain remained on his finger, and attached to it was a piece of rock. Zeus agreed to grant Prometheus his freedom if he wore the link as a reminder of his sin. Later a ring set with a sapphire replaced the link and stone. Sapphire symbolizes truth, sincerity and constancy. It was believed to protect the wearer against capture by an enemy, and to win the favour of princesses. It also protected against poison. It was said that if a poisonous snake were put in a vessel with a sapphire, the rays from the gem would kill it. The name sapphire originally comes from Sanskrit. It became sappheiros in Greek, meaning blue. Before the value of sapphire was known to them, villages in the Zanzkar mountains of Kashmir (India) used the gem as a flint to start fires.

Cuts & Uses
Faceted and en cabochon, usually mixed cut, beads, carved (poor quality). Synthetic sapphire is used in watches, precision instruments and electronic equipment.