Ruby is the most valuable variety of the corundum mineral species, which also includes sapphire.
Traces of chromium give this red variety of the mineral corundum its rich color. Long valued by humans of many cultures. In ancient Sanskrit, ruby was called ratnaraj, or “king of precious stones.”
A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum
Rubies have always been held in high esteem in Asian countries. They were used to ornament armor of noblemen in India and China.