Collection: December Birthstone Jewelry

Three stones, three completely different histories

December is the most crowded month on the birthstone list. Turquoise is one of the oldest gems in human use — mined in Egypt and Persia thousands of years ago, central to Indigenous jewellery traditions across the American Southwest, and worn almost everywhere it could be traded. Zircon is the geological elder: some zircon crystals are the oldest known material on earth, dated past four billion years. Tanzanite is the infant, discovered in northern Tanzania in 1967 and found in commercial quantity nowhere else on the planet.

Zircon also deserves rescuing from a name problem. Zircon is a natural mineral with high dispersion — it throws real fire, close to diamond. Cubic zirconia is a manufactured stone with a similar-sounding name and no relationship to it. They are constantly confused. Where a piece here uses cubic zirconia, it is called cubic zirconia.

What December's stones are for

Turquoise is the protection and safe-travel stone, and that meaning is remarkably consistent across cultures that had no contact with each other. It sits at the throat: honest speech, and the older idea of protection while you are away from home. Tanzanite is a third-eye stone — intuition, perspective, the longer view. Zircon is worn for grounding and clarity.

For a December birthday, the combination is unusually well suited to the month: protection, perspective and light, at the point in the year when the days are shortest. More on all three in the December birthstone guide.

Turquoise is heavily treated — and heavily faked

More than most stones, turquoise on the open market has been altered. Stabilised turquoise is genuine turquoise impregnated with resin to harden it, and it is both extremely common and entirely legitimate — untreated turquoise is soft and porous enough that most of it would not survive being set. Reconstituted turquoise is powder bonded back together. Dyed howlite is a different white mineral coloured to look like turquoise, and it is the one sold most often under a name it has no right to.

Each listing here names what it is: genuine turquoise, stabilised turquoise, or dyed howlite. Dyed howlite is a good-looking material at a fair price and it is never described as turquoise.

Care — turquoise is the fragile one

Turquoise is 5 to 6 on Mohs, soft and porous. It absorbs oils, perfume, hairspray and cleaning products, and once it does the colour shifts — often greening — permanently. No soaking, no ultrasonic cleaner. Wipe with a dry or barely damp cloth. Put it on last and take it off first.

Tanzanite is 6 to 7 but has perfect cleavage and is sensitive to sudden temperature change and to ultrasonic cleaning — treat it as a pendant-and-earring stone rather than an everyday ring. Zircon is harder but brittle at the facet edges, so it abrades if stored loose against other jewellery. Full routine in the crystal care guide.

Wearing it and gifting it

Turquoise is a silver stone by long tradition and it looks right there — the cool metal keeps the blue clean. Gold pushes it toward its green undertone, which can be beautiful and is a different look entirely. Tanzanite's violet-blue is happiest in silver or white metal, where nothing warms it.

The practical note for December: a birthday inside the holiday fortnight tends to get absorbed into it. A stone that is specifically theirs — named, explained, not wrapped in the same paper as everything else — is the whole point of buying by birth month.