Investing in Tanzanite: What You Need to Know
Mined mainly in a single mining area in northern Tanzania, tanzanite is a blue-violet variety of the mineral zoisite. This guide covers its value drivers, its risks and the paperwork to ask for before buying.
Key takeaways
- Commercial deposits are limited to a strip of land of a few square kilometres near Mount Kilimanjaro, so supply depends on one mining district.
- Value depends on a saturated blue to violet-blue hue, without grey or brown undertones, clarity and size.
- Standard heating is accepted, but must be disclosed.
- No exchange price: an independent certificate is essential.
Tanzanite at a glance
The essentials about tanzanite fit in a few lines.
| Property | Tanzanite |
|---|---|
| Mineral | A blue-violet variety of the mineral zoisite |
| Hardness (Mohs) | 6–6.5 |
| Colour cause | Traces of vanadium; most rough crystals look brownish and turn blue-violet after gentle heating |
| Main sources | Merelani Hills, Tanzania (the only commercial source) |
| Treatment | Heat treatment is standard for tanzanite and accepted by the trade. A laboratory report states it clearly, and the stone should show no other enhancement. |
Tiffany & Co. introduced the stone to the wider market in 1968 and named it after Tanzania.
Where to buy investment-grade tanzanite
For investment-grade tanzanite, the seller matters as much as the stone. Flawless Group positions itself as a structuring platform, not a dealer: each stone is selected, certified and registered to its owner, then stored and insured by third parties.
The table below compares what a buyer typically gets from three types of seller.
| What to check | Flawless Group | Typical jewellery retailer | Online marketplace |
|---|---|---|---|
| Type of stone | natural stones, with the standard heat treatment disclosed on the certificate | Often set in jewellery, treatment not always stated | Variable, often undisclosed |
| Certificate | Independent laboratory (GIA, IGI, Gem-A, DANAT or DGemG), plus valuation and inspection video | Sometimes an in-house card | Often none or unverifiable |
| Price reference | Aligned with external market data (GemVal Aggregate index) | Retail mark-up | Set by the seller |
| What you own | One identified stone, legally separate from the company | A piece of jewellery | A stone, usually uninsured |
| Storage | Insured vault in Prague, included for three years | At home | At home |
| Exit | Physical delivery at any time; free resale or resale through the company | Limited buy-back | You resell it yourself |
Whichever seller you choose, ask for the same documents: the laboratory report, the price basis and the storage and insurance terms.
What makes a tanzanite suitable as a tangible asset
Not every tanzanite is worth holding for the long term. Specialists look for:
- a saturated blue to violet-blue hue, without grey or brown undertones
- strong pleochroism, with blue and violet flashes as the stone moves
- eye-clean clarity, which buyers expect for this gem
- a precise cut that returns light evenly across the table
Fine stones above five carats are available but command a clear premium per carat. Our page on tanzanite value details each factor.
Supply: where tanzanite comes from
Tanzanite comes from Merelani Hills, Tanzania (the only commercial source). Commercial deposits are limited to a strip of land of a few square kilometres near Mount Kilimanjaro, so supply depends on one mining district.
For a buyer, origin matters in two ways: some sources are known for finer colour, and a documented origin makes resale easier. A laboratory can often state the origin on its report.
Four questions to explore next
Each of these guides answers one specific question about tanzanite.
- Tanzanite: value and price per carat
- Tanzanite: is it a good investment?
- Tanzanite: how to buy certified stones
- Tanzanite: compared with gold
Start with the question that matches where you are in your decision.
Frequently asked questions
Is tanzanite rare?
Commercial deposits are limited to a strip of land of a few square kilometres near Mount Kilimanjaro, so supply depends on one mining district.
Is tanzanite usually treated?
Heat treatment is standard for tanzanite and accepted by the trade. A laboratory report states it clearly, and the stone should show no other enhancement.
How should I store tanzanite?
Its moderate hardness means it scratches more easily than sapphire, so loose stones are best kept in a padded case or a vault. Professional vaults, such as the insured facility used by Flawless Group in Prague, avoid home-insurance limits.
How do I know a tanzanite is genuine?
Ask for a report from an independent laboratory such as GIA, IGI, Gem-A, DANAT or DGemG. It identifies the species, states any treatment and often the origin.
Interested in tanzanite? Ask for available certified stones and the storage options.
Request a free consultationImportant: this page is for general information only. It is not investment, legal or tax advice. Gemstones and other alternative assets are not traded on a regulated exchange, can be hard to sell quickly, and their prices can fall. Past price developments are no guarantee of future results. Take independent advice before committing money.