The December birthstone, known as tanzanite, is a beautiful and unique gem.
It's often described as "velvety," mostly because of the deep and saturated color that ranges from a pure rich blue to violet. The blue is considered most valuable.
This December birthstone (6 to 7 on the Mohs scale of hardness) is resistant to the effects of normal heat, light and common chemicals. Still, the December birthstone may crack if exposed to very high temperatures or sudden temperature changes, and it abrades easily. It can be attacked by hydrochloric and hydrofluoric acids.
Most tanzanite begins as brownish zoisite that is heat treated to produce the blue to violet hues that characterize this December birthstones. The resulting color is permanent, and there are no additional durability concerns.
Your tanzanite birthstone is best set in earrings or pendants. While not recommended for daily wear in a ring, with a protective mounting and some care this December birthstone can be an attractive special-occasion jewel.
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