Sapphire
Star Sapphire
| Category |
| Corundum |
| Crystal Form |
| Trigonal |
| Moh's Scale Hardness |
| 9.0 |
| Specific Gravity |
| 3.97–4.05 |
| Refractive Index |
| 1.76–1.78 |
| Sources |
| Afghanistan, Australia, Cambodia, India, Kenya, Myanmar, Pakistan, Russia, Tanzania, Thailand, United States (North Carolina) and Vietnam. |
Sapphire comes from the Latin word "Sapphirus" meaning blue. Sapphire was a favourite stone for rings and brooches of medieval kings in Europe and beginning in the 11th century it has became the perferred stones for rings for religious orders.
Inclusions
When needle (rutile) inclusions exist and are aligned, asterism occurs in the gemstone. These stones are cut en cabochon to display the 6-rayed stars, and are known as "Star Sapphire".
Treatment
Sapphires are commonly heat treated to enhance their colour.
Caring
Due to their hardness and durability, almost any cleaning technique is acceptable
Like rubies, sapphires are more durable then the metal mounts/prongs on your jewellery, so check the prongs occasionally to assure a secure fit.
Never put sapphires in boiling hot water.