Ruby

Rubies are one of the hardest known minerals.  With a hardness of 9 on the Mohs scale, it is only softer than a diamond.  Rubies are known for their beautiful red color.  A ruby is a variety of the mineral corundum.  The gemstone sapphire is also a variety of corundum and comes in many colors, except for red.  Rubies have a glassy luster which makes them shiny.  Rubies are most commonly used for jewelry.  Rubies are commonly mined in Myanmar, Thailand, Kenya, the United States, Sri Lanka and Tanzania.  In 2005, a 440 carat ruby was discovered and thought to be one of the largest gems found to date.