Scientific Name: Red/pink variety of corundum

Group: Oxides

Chemical composition: Al2O3

Colors: Red – pink color is caused mainly by the presence of the element chromium

Hardness: 9

Formation: Hexagonal – trigonal crystal; pyramidal, prismatic barrel-shape form

Principal Sources: Thailand; Myanmar, Sri Lanka; Afghanistan; Madagascar; Vietnam; Cambodia; North Carolina, Montana, USA

Special Notes: The ruby is considered one of the four precious stones, together with the sapphire, the emerald, and the diamond. Its name comes from ruber, Latin for red. Blue varieties of gem-quality corundum are called sapphires. It was believed by ancient Hindu and Burmese miners that colorless or pale pink sapphires were rubies that had not completely ripened.