| Name: | Corundum - Ruby and Sapphire |
| Derivation: |
From "kurundum" (Tamil) From "rubeus" (Latin) red From "sappheiros" (Greek) lapis lazuli |
| Formula: | Al2O3 |
| Description: | Very hard crystal. Red corundum is ruby (left). Blue curundum is sapphire (right). Or you can just have corundum (below right). |
Corundum is a very hard stone. Another name of Corundum is Emery, and Emery paper is used for rubbing things smooth.
Sapphire was originally the name of lapis lazuli. The name of sapphire was Hyacinthus, because they were supposed to look like the flower. Now Hyacinthus is another name of zircon (which looks nothing like sapphire!)
Romans used Sapphires for the development of greater trade with India at the time of the Emperor Trajan.