7.0 on the Mohs scale.
Madagascar, North America, Brazil, Myanmar (Burma), Africa, Siberia, Australia, Sri Lanka (Ceylon). Tourmaline and opal are the birthstones of the month of October. Tourmaline is the national gemstone of the United States.
Colored by Chromium, these are the more valuable green tourmalines. Can be confused with emerald and tsavorite garnet.
Chrome tourmaline is not enhanced.
More information on gemstone enhancements.
Chrome Tourmaline is a member of the Tourmaline gemstone family.