Tanzanite as a December Birthstone: Why It Makes a Meaningful Gift

Round about October, the emails change. Fewer people ask about game drives and more ask some version of the same thing: my wife, son or best friend has a December birthday, what do I get them? I've got an obvious answer, and it's sitting in a display case next door. The tanzanite December birthstone is the youngest stone on the birthstone list, and I'd argue it's the one with the best story.

I'm biased, of course. I work at Safariland near Karatu, a few hours' drive from the only hills on earth where this stuff comes out of the ground. So take that into account. But I've also watched a lot of people choose tanzanite as a gift, and some of what they've learned is worth passing on.

How tanzanite became a birthstone

The short version goes like this. In 1967 someone found blue crystals in the Merelani Hills, near Arusha. (Who exactly found them first is still argued about locally, and I'm not going to settle it here.) A year later Tiffany & Co. named the stone tanzanite and started selling it as something you could only get from one country.

Then in 2002, the American Gem Trade Association put it on the December birthstone list alongside turquoise and zircon. It was the first new stone added to the list in about fifty years. I like pointing out to people that anyone born before 2002 grew up without tanzanite as their birthstone. It arrived during their lifetime. Put that on the gift card. People like it.

Why I think it makes a good gift

There's no tanzanite anywhere else. That's the first thing. Geologists have looked, and so far the Merelani deposit is it, a strip of hillside a few kilometres long. So a tanzanite ring bought in London or Toronto or Dubai started its life in the same small corner of northern Tanzania. You can point to it on a map.

The second thing is the colour, which doesn't sit still. Tanzanite is what gemmologists call trichroic. Turn it one way and it's blue. Turn it another and it goes violet, and now and then you catch a flicker of something deeper, almost burgundy. Under a warm lamp at dinner it leans purple. Take it outside in the morning and it's bluer. I've watched people receive a tanzanite pendant and spend the next five minutes tilting it under the light, which, if you're the one giving it, is a very nice five minutes.

And then there's the story bit. Lots of jewellery is pretty. Not much of it comes with a discovery date, a place and a reason it's yours.

Tanzanite and the other December birthstones

December's a bit greedy, with three official stones. If you're torn between them, this is roughly how they stack up:

Choosing a tanzanite gift

Look at the colour first and worry about size later. Deep, saturated blue-violet is what the trade values most, but I'll be honest, some of my favourite stones are the paler lilac ones. They suit people with softer colouring. Look at any stone you're considering in daylight and then indoors, because it does change, sometimes a lot.

You'll hear that most tanzanite has been heat-treated. True. Nearly all of it is gently heated to bring out the blue, and that's been normal practice for decades, so it's nothing to panic about. What matters is that the seller tells you, plainly, and gives you something in writing about what you've bought. If they get vague, walk away. Our guide on how to tell if tanzanite is the real thing has the checks I'd make myself.

Then think about the person's hands. Tanzanite is softer than sapphire, around 6 to 6.5 on the Mohs scale, and a hard knock can chip it. If she gardens every weekend or he plays cricket, I'd steer you towards a pendant or earrings. A ring can still work, but get a setting where a bit of metal wraps the edge of the stone.

Something for most budgets

You really don't need a big stone. A small one with good colour in a plain pendant often looks better than a large, washed-out one, and it gets worn a lot more. Studs are the other safe place to start.

For a fortieth, a sixtieth, an anniversary that lands in December, that's when people tend to go bigger: a ring, or a drop pendant with a decent-sized stone. Some like a ring of small diamonds round the tanzanite, which makes the blue look sharper. Others think that's fussy and want the stone on its own. Both camps are right.

Metal changes things too, more than you'd expect. In white gold or platinum tanzanite looks cool and blue. Yellow gold warms it up and pulls out the violet. If you know what they normally wear, match that.

Looking after it

Warm water, a drop of mild washing-up liquid and a soft toothbrush, then dry it with a cloth. That's all the cleaning it needs. Keep it out of ultrasonic and steam cleaners, which can damage it, and store it in its own pouch so a diamond ring doesn't scratch it in the drawer. Rings should come off for the gym and the washing up. Most people have no idea about any of this, so I'd tuck a little note in with the box.

Write a proper note

While you're writing that care note, add a line or two about where the stone came from. Found in 1967. Made a December birthstone in 2002. Mined only in Tanzania. If you bought it here, say where and when. It sounds like a small thing. It's the bit people keep.

Buying it close to the source

If you're on safari in northern Tanzania before December, I'd buy it here, and not only because I work next door. At Safariland, Africa Gems & Jewelers runs the Tanzanite Tour, which follows the stone from the mines through to finished jewellery. You see stones being cut and set, and if nothing in the cases is quite right for the person you're buying for, you can ask about having something made.

Even if you leave empty-handed, you'll be far harder to fool in a shop back home. Have a read of our comparison of tanzanite gem tours and buying in a shop, and our guide on why tanzanite jewellery is so rare and how to buy it right, before you come.

Not travelling? Ask the team about shipping. Just don't leave it until the middle of December, because everyone else has the same idea.

Frequently asked questions

Is tanzanite the official December birthstone?

Yes. The American Gem Trade Association added tanzanite to the modern December list in 2002. Turquoise and zircon are the other two.

Where does tanzanite come from?

Only from the Merelani Hills near Arusha, in northern Tanzania. Nobody has found a commercial deposit anywhere else.

Is tanzanite hard enough to wear every day?

It's about 6 to 6.5 on the Mohs scale, so it needs a bit of care. Pendants and earrings are the easiest for daily wear. Rings are fine with a protective setting.

Can I buy tanzanite while I'm on safari?

Yes. Africa Gems & Jewelers at Safariland near Karatu runs the Tanzanite Tour and sells tanzanite jewellery, and they can talk to you about custom pieces.