A ruby is a precious gemstone known for its deep red color. It is a variety of the mineral corundum (aluminum oxide) and gets its red color from the presence of chromium. Rubies are one of the traditional “Big Four” […]
A ruby is a precious gemstone known for its deep red color. It is a variety of the mineral corundum (aluminum oxide) and gets its red color from the presence of chromium. Rubies are one of the traditional "Big Four" gemstones, along with sapphires, emeralds, and diamonds.