Understanding the quality of tanzanite is essential for making a sound purchase.

Almost all tanzanite is heat-treated to transform its natural brownish hue into the stunning blue and violet colors seen in jewelry.

Tanzanite has a rating of 6.5–7 on the Mohs hardness scale. While suitable for jewelry, it should be treated with care to avoid chipping. It is not recommended for daily, rugged wear (like gardening or intense sports).

The Definitive Tanzanite Buying Guide - The Rare Gemstone Company