How Much Is Tanzanite Worth?
A blue-violet gem found in exactly one place on earth — rarer than diamond in the ground, yet surprisingly affordable in the shop. You pay for colour.
Tanzanite is the blue-to-violet variety of the mineral zoisite, discovered only in 1967 near Mount Kilimanjaro and named by Tiffany & Co. after its one and only source: the Merelani Hills of Tanzania. That single-source rarity is its whole story — and the reason experts warn the supply is finite. Yet, oddly, it remains one of the best-value blue gems you can buy.
What drives the price: colour and size
Value is almost all about colour: the most prized is a deep, saturated violet-blue (or blue-violet), rich but not so dark it goes inky. Pale, greyish or overly light stones sit at the bottom. Size matters too — larger stones with deep colour are much scarcer, so per-carat prices rise with weight. Nearly all tanzanite is gently heated to reach that blue; this is standard and accepted, and truly unheated material is a niche collector premium.
Typical fair prices
Faceted, eye-clean, well-cut tanzanite, mid-2020s retail. Bigger, deeply coloured stones command higher per-carat prices — the opposite of an abundant stone like amethyst.
| Grade | Fair $/ct | Notes |
|---|---|---|
| Pale / small | $50–$150 | Light or greyish; entry level |
| Good blue-violet | $150–$400 | Nice saturation — the value sweet spot |
| Fine deep (AAA) | $400–$800 | Rich violet-blue, larger sizes |
| Exceptional / large | $800–$1,500+ | Top colour, 5 ct+ or vivid “block D” |
To sanity-check the “good blue-violet” sweet spot on finished jewellery, our sister site Minerals Kingdom keeps a photographed tanzanite collection against a neutral background — a useful reality check before paying up for a deeper grade.
Watch-outs
- Over-dark or “windowed” stones. Colour that goes inky, or a pale “window” through the middle from a poor cut, lowers value — don’t pay premium for either.
- Coated or foil-backed tanzanite. Thin coatings can deepen colour on cheap stones. Legitimate only if disclosed — and worth far less.
- Synthetic “tanzanite.” There’s no common natural substitute, but lab-created forsterite or coated glass is sometimes sold as tanzanite. A quick lab check settles it.
- Softness ignored. Tanzanite is only 6.5–7 Mohs with easy cleavage — it’s a pendant/earring stone more than a daily ring. Don’t overpay for something you’ll chip.
- “Unheated” hype. Nearly all tanzanite is heated and that’s normal; a small unheated premium exists but only matters to specialist collectors.
The GIA’s tanzanite quality factors rank deep, saturated violet-blue highest and note that routine heat is standard. The International Gem Society covers its single source and its care needs.
Buy tanzanite by colour, not just carat
Our sister marketplace shows colour, size and any treatment — so you can pay for the violet-blue, not the weight alone.
Browse tanzanite at Minerals Kingdom →FAQ
Why is tanzanite so cheap if it’s rare?
It’s a supply-and-demand quirk: tanzanite comes from a single small area in Tanzania (rarer in the ground than diamond), but demand is far smaller than for sapphire or diamond, so prices stay moderate. Many see that as a bargain on genuine rarity.
Is heated tanzanite worth buying?
Yes. Almost all tanzanite is heated to reach its blue-violet colour, and this is standard and accepted. Unheated stones exist but carry only a small, collector-focused premium.
Can I wear tanzanite every day?
Cautiously. At 6.5–7 Mohs with cleavage, it scratches and can chip more easily than sapphire, so it’s best as earrings or a pendant, or an occasional ring — not a knock-about daily band.
Does bigger tanzanite cost more per carat?
Yes. Unlike abundant stones, deeply coloured tanzanite gets scarcer with size, so larger fine stones command higher per-carat prices.
More value guides
Sources
Gemological Institute of America (GIA) — tanzanite quality factors & heat treatment. International Gem Society (IGS) — tanzanite information, single source & care. Price ranges are Fair Carat’s synthesis of mid-2020s online retail; verify current dealer prices before buying.Independent gem-value research. We don’t sell stones and sellers can’t buy a better verdict.
Informational only — not a formal appraisal. For insurance or resale, get a certified appraisal.