Tanzanite Beads

Frequently asked questions

• Where does tanzanite come from?

  Tanzanite is found in only one place on Earth: the Merelani Hills (also spelled Mererani) in northern Tanzania, near Arusha and Mount Kilimanjaro. The mineralized zone is roughly seven kilometers across and is divided into four mining blocks. The deposit was first identified in 1967, and Tiffany & Co. introduced the material commercially as "tanzanite" the following year. There is no second commercial source — every tanzanite bead traces back to this Tanzanian zone.
• Is tanzanite heat-treated?

  Essentially all commercial tanzanite is heat-treated. Natural rough is typically brown or yellow-brown zoisite; controlled heating to roughly 600°C converts the vanadium chemistry and produces the blue-violet color the market knows the stone for. This is standard industry practice openly disclosed by the AGTA, GIA, and the tanzanite trade itself. The treatment is permanent and stable under normal wearing conditions. Untreated blue-violet tanzanite exists but is rare enough to belong to the collector market; assume bead-trade tanzanite is heat-treated unless a specific strand documents otherwise.
• Why are tanzanite beads usually small?

  The material's rarity and the cutting economics. Tanzanite comes from a single small deposit and is mined in limited quantities; larger and higher-grade rough is cut for faceted ring and pendant stones, where it commands far higher per-carat prices than drilled beads. The bead trade works with smaller rough, so the cuts run small: 2mm to 5mm faceted and microfaceted rounds, 1x3mm to 4mm faceted rondelles, 3mm table-cut cubes, 4mm faceted coins, small ovals, and top-drilled teeth. Larger tanzanite rounds (8mm and above) exist but are uncommon and priced accordingly.
• How can I tell if my tanzanite is real?

  Three signals. First, pleochroism — real tanzanite shows different colors (blue, violet, sometimes burgundy under incandescent light) when rotated; glass simulants and dyed quartz substitutes do not. Second, color register — real tanzanite is a saturated blue-violet, not a flat blue or a flat violet; substitutes often lack the violet undertone.
• How durable is tanzanite for jewelry?

  Mohs 6.5–7 — reasonably hard, but tanzanite has perfect cleavage in one direction, meaning a sharp impact along that plane can fracture the stone. Standard care: soft cloth with mild soap; avoid ultrasonic and steam cleaning; avoid sharp impact. Tanzanite is well-suited to necklaces, earrings, and bracelets worn with ordinary care; it is less ideal for rings or pieces exposed to repeated impact. Heat-treated material is color-stable under normal wear and does not fade in ordinary sunlight.