Corundum has been historically known by many names: ruby, sapphire, hyacinthos, asteria, adamant, etc. Originally named "corinvindum" in 1725, this gemstone's current name was derived from the Sanskrit wordkuruvinda(meaning "ruby"). The spelling "corundum" was first used in 1794.
Corundum is somewhat the off-brand version of the more "name brand" gemstones ruby(the red corundum) and sapphire (the other colors). Corundum is very hard, tough and stable, making it ideal for a variety of industrial uses, especially materials which do not reach gem grades. A black variety, known for its use as a high-quality abrasive, is the emery that emery boards were originally named for.
Tiny shaped pieces of corundum were used in Swiss watches during the mid-1800s, as their durability and wear-resistance made them ideal for long-term use. In this use, they were called "jewel bearings"--watches using them were said to have "jewel movement"--so this longevity and precision added to the reputation of Swiss watches.
Corundum is said to promote insight into the unknown, promoting wisdom and wise choices. It is also believed to subdue emotional tumult by relieving tension, releasing anger in a positive manner and reducing the presence of negative thoughts. It is also believed to enhance intuition.
Some practitioners use corundum by color, by assigning different colors of this stone to the appropriately colored chakras, and highlighting those characteristics. In addition, while it is not a birthstone in itself (as ruby and sapphire are), corundum has been affiliated with the zodiac sign Sagittarius.
