9.0 on the Mohs scale.

Myanmar (Burma), Thailand, India, Sri Lanka (Ceylon), Tanzania, Afghanistan, Australia, Brazil, Cambodia, Malagasy Republic, Malawi, Pakistan, Zimbabwe (Rhodesia), United States (Montana, North Carolina).

Sapphire is occassionally found with such color-zoning, that the crystals make interesting bi-colored gems.

Bi-color sapphire is always heat treated to produce, intensify or lighten color and/or improve color uniformity and appearance.

More information on gemstone enhancements.

Bi-Color Sapphire is a member of the Sapphire gemstone family.