Peridot is a magnesium iron silicate mineral with a hardness of 7. Its crystal system is orthorhombic and it generally forms in short, compact prisms which are vertically striated. Its olive to lime green colour is caused by iron. The name Peridot is of Greek origin, but the original meaning is not known. Chrysolite is a name sometimes used to describe yellow-green Peridot, and this name is derived from the Greek words meaning ‘gold’ and ‘stone’.