The Ruby has been known since before the bible.
In 1890 the ruby was listed as the most valuable of the corundum family of stones. Today a high quality ruby can still be much more valuable than a diamond.
Corundum is the extremely hard and abrasive, or scratchy, type of stones.
The name ruby comes from the Latin word rubeus, 'red'.
An asterism is a starlike play of light from a polished stone, or mineral, especially sapphires.
Sometimes other stones such as garnets, ruby spinels, red quartz, or red tourmaline get passed off as a ruby. But the true ruby will easily scratch all of these other stones.
The true ruby will turn green under the flames of a blow-pipe, but when cooled off it goes back to its original color.
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Take a look at some famous Star Rubies
Take a look at the Black Prince's Ruby in the crown of the King of England
