Tanzanite: The Rare Blue-Violet Stone and How to Buy It
Tanzanite is a blue-violet stone with a colour somewhere between a sapphire and an amethyst, and a story no other gem can match: it comes from a single small area on earth, near Mount Kilimanjaro in Tanzania. That makes it genuinely rare. It is also softer and more delicate than it looks, so it needs a bit of care. Here is how to buy tanzanite and wear it so it lasts.
We set tanzanite at our Coquitlam bench for December birthdays and for people who want that unusual violet-blue. It is a lovely stone, as long as you know its limits.
One source, one colour like no other
Tanzanite is a blue-violet variety of the mineral zoisite, and it was only discovered in the 1960s, found in commercial quantity in just one place in northern Tanzania, which is where its name comes from. That single source is a big part of its appeal and its price. It became the modern December birthstone in 2002, according to the GIA.
Its other trick is pleochroism: tanzanite shows different colours from different angles, flashing blue, violet, and sometimes a burgundy tone as you turn it. A cutter chooses how to orient the stone to bring out the most blue or the most violet. The richest, deepest blue-violets are the most valuable.
Almost all tanzanite is heated
In the ground, most tanzanite is a dull brownish colour. Gentle heating turns it the blue-violet we know, and this treatment is routine, stable, and permanent, as the GIA describes. It is a normal and accepted part of how tanzanite reaches the market, so you can buy a heated stone with confidence.
The important part: it is delicate
This is where tanzanite differs from the tougher stones earlier in this series. It rates only about 6 to 7 on the Mohs hardness scale, according to the GIA, and it has cleavage, meaning it can split along certain directions if struck the wrong way. So tanzanite is not the best choice for a ring worn hard every day. It shines as a pendant or a pair of earrings, where it takes few knocks, and it can work as an occasional-wear or carefully-set ring.
Care matters too. Clean tanzanite only with warm water, mild soap, and a soft brush. Never put it in an ultrasonic or steam cleaner, and avoid sudden temperature changes, because the vibration and heat can crack it, as the GIA care guidance warns. It is a similar care story to opal: a beautiful stone that rewards gentle handling.
| Property | Tanzanite |
|---|---|
| Mineral | Blue-violet zoisite |
| Source | One area in Tanzania only |
| Mohs hardness | About 6 to 7, with cleavage |
| Special trait | Pleochroic: blue and violet from different angles |
| Treatment | Heat, routine and stable |
| Best worn as | Pendant or earrings; ring with care |
Who tanzanite suits
Tanzanite suits someone drawn to its rare violet-blue and its single-source story, especially for a December birthday, and someone happy to treat it gently. For a pendant or earrings it is a wonderful choice with little to worry about. For a ring, choose a protective setting, take it off for anything rough, and clean it by hand. Handled that way, tanzanite gives you a colour and a rarity that few other stones can. If you want the same blue tone in something you never have to think about, a sapphire is the harder, more everyday option.
Key Takeaways
- Tanzanite is a rare blue-violet zoisite found in only one place on earth, in Tanzania.
- It is pleochroic, flashing blue and violet from different angles, and almost always heat-treated (stable).
- At Mohs 6 to 7 with cleavage, it is delicate, better as a pendant or earrings than a hard-worn ring.
- Clean it only by hand, never ultrasonic or steam, and avoid knocks and sudden temperature changes.
Frequently Asked Questions
Is tanzanite durable enough for a ring?
Only with care. Tanzanite is about 6 to 7 on the Mohs hardness scale and has cleavage, so it can scratch and even split from a hard knock. It is better suited to pendants and earrings. As a ring, it needs a protective setting, gentle handling, and removal for rough tasks.
Why is tanzanite so rare?
Because it comes from a single small deposit near Mount Kilimanjaro in Tanzania, and nowhere else on earth. That one source, combined with strong demand, is why tanzanite is considered rare and why fine stones can be expensive.
Is tanzanite treated?
Almost always. Most tanzanite starts brownish and is gently heated to bring out its blue-violet colour. The treatment is routine, stable, and permanent, and it is a normal, accepted part of the trade, so a heated tanzanite is what you should expect to buy.
How do you clean tanzanite?
Only with warm water, mild soap, and a soft brush, then pat dry. Never use an ultrasonic or steam cleaner, and avoid sudden temperature changes, because tanzanite's cleavage makes it prone to cracking under vibration or thermal shock.
Sources
- GIA — Tanzanite (source, hardness, treatment)
- GIA — Tanzanite Care and Cleaning
- GIA — Birthstones (tanzanite, December)
Data sourced 19 July 2026. If you spot something out of date, tell us and we will update the guide.
Visit Vanhess
We are a family-run studio at 2929 Barnet Highway, Unit 2424 in Coquitlam, with an on-site goldsmith. Come see tanzanite's blue and violet shift in the light, or call us at +1 (604) 653-6449. We can set it safely as a pendant, earrings, or a protected ring. Browse our pendants to start, or ask about a custom December birthstone piece.
