Peridot is the gem variety of olivine. It has a hardness of 6.5 – 7 and a specific gravity of 3.8. Its name is probably derived from the Persian word “pharidat”, which means gemstone.
The peridot was known since ancient times. The Romans knew and used the peridot, which they called “evening emerald”. It is one of the few gems that appear consistently with a single color. The greater the iron content the more intense its pigmentation.