Mineral Spotlight- Corundum

✨It’s time for another Mineral Spotlight Monday, a weekly post series discussing the properties of various minerals.

This week we’re talking about corundum; the mineral name for ruby and sapphire. (Actually, any color other than red is often referred to as "sapphire".)

Corundum is the crystalline form of aluminum oxide.  If traces of chromium are present then a red "ruby" is produced.  Iron and titanium create the rich blue hues of the common "sapphire". 
As a very hard and durable mineral (9 on the Mohs scale), you'll often see it used in jewelry.
Corundum has a rich history of uses, aside from appearing in the jewelry of royalty throughout the ages.
A variety of corundum referred to as "emery" was originally used in making emery boards for nail care.
In the 1800's, watchmakers in Switzerland began using corundum within the gear structures of watches. The hardness of the material meant that the moving parts wouldn't wear out as quickly and would guarantee a more reliable time piece.
Did you know that the first laser incorporated the use of synthetic ruby?
And if you have scanned a barcode at the grocery store, the clear plate over the laser lights is probably made of corundum!
Where is it found?
The most exquisite rubies have been found in Myanmar, Thailand and Sri Lanka. Sapphires are found in the same locations with a highly sought after hue being found in the Kashmir region of Pakistan and India.
Have any corundum in YOUR collection?