.65" Blue Corundum (Sapphire) Crystal - Malawi

Sapphire is a variety of corundum and one of the most popular gemstones for both its alluring colors and hardness--9 on the Mohs hardness scale--making it suitable for nearly all types of jewelry. Corundums of gemstone quality of all colors, except red, are called sapphire. Red varieties are called rubies. The various colors of sapphire are qualified by description, e.g., green sapphire or yellow sapphire. Colorless sapphire is called leuko-sapphire and pinkish orange sapphire is called Padparadscha.

Historically, the name sapphire used to be applied to various stones. As late as the Middle Ages, the name sapphire was understood to mean what is today described as lapis lazuli. Around 1800 it was recognized that sapphire and ruby are gem varieties of corundum. At first the only blue variety was called sapphire, and corundums of other colors (with exception of red) were given special, misleading names, such as "Oriental peridot" for the green variety and "Oriental topaz" of the yellow type.