This yellow-green stone, also called olivine when it is an olive-green shade, was introduced to Europe by knights returning from the crusades. Extracted from mines on Zabarjad, a small island in the Red Sea also known as Saint John's Island, it captured the imagination of Eastern civilizations almost three thousand years ago. Reaching this island was so difficult that sailors named the peridot topazion from the Greek word meaning “to seek”, a name it kept for many centuries before being supplanted by the French term. The peridot is associated with diamonds, as it is one of the components of the diamond’s matrix rock, kimberlite, to which it gives its distinctive blue-green color. Peridot was the favorite stone of King Edward VII. Its popularity surged in the early twentieth century and has never diminished. Silicate of ferrous magnesium. Hardness: 6.5 to 7. Birthstone of the month of August. Its planet is Saturn. Symbol of health and protection. United States, Australia.