Peridot, the August birthstone, is an otherwordly stone. It is formed far below the surface of the Earth and transported upward by molten lava, and it is also found in meteorites. In 2005 peridot was found in comet dust brought back from a space probe. The ancient Egyptians even called called peridot "the gem of the sun." Not only is it peridot the August birthstone, it's also the stone for a 15th anniversary. It’s easy to see why this breathtaking green gem is believed to possess otherworldly qualities.