Peridot is one of the few gemstones that occur in only one color: an olive-green. The intensity and tint of the green, however, depends on the percentage of iron in the crystal structure.
Peridot has a very long written history. Ancient papyri record the mining of these stones as early as 1500 BC. The main source in the ancient world was Topazo Island (now Zabargad or St. John’s Island) in the Egyptian Red Sea.