Tanzanite

Wholesale tanzanite — buying guide for the trade

Found in a single ~5km strip of Tanzania's Merelani Hills. Strong blue-to-violet pleochroism, almost always heated to reveal its signature colour.

Key properties

Mineral

Zoisite (Ca₂Al₃Si₃O₁₂(OH))

Hardness

6.5 (Mohs)

Key origins

Tanzania only (Merelani Hills)

Typical treatments

Heat (universal and accepted)

What to look for when buying wholesale

• Block-D AAA grading is the trade standard for tanzanite quality.
• Calibrated cushions, ovals and trillions trade in volume from Jaipur cutters.
• Tanzanite is brittle — favour protective settings.

Certification guidance

GIA or IGI for anything above USD 1,000. Origin is uncontested (Tanzania), so reports focus on grade and treatment.

Treatment disclosure

Heat is universal and accepted — undisclosed in most invoices but assumed industry-wide.

Typical wholesale price tiers

Prices are indicative wholesale-to-trade ranges. Actual offers depend on origin, certification and supply at the time of enquiry.

Cuts and shapes

Tanzanite is faceted into the same core shapes seen across coloured stones and diamonds — round, oval, cushion, emerald-cut, pear, radiant, princess, asscher, marquise and heart — plus antique cuts such as old mine and old European, most associated with period diamond jewellery. See the full Cut Library →