The December birthstone turquoise is one of the oldest gems in human use, worn in Egypt and Persia thousands of years ago and central to jewelry traditions across the American Southwest. It is also the birthstone most likely to be misunderstood at the counter, because turquoise is porous, frequently treated, and behaves differently from the crystalline stones people are used to. Here is what turquoise is, what it has meant to the cultures that treasured it, how to choose a December gift when the calendar is already full, and how to keep the stone from changing color.

What turquoise is

Turquoise is a hydrated phosphate of copper and aluminum that forms near the surface, where water carrying those elements seeps through rock in arid regions. Copper gives it the blue; iron pushes it toward green. It is opaque rather than transparent, which is unusual among the major birthstones and part of why it reads as jewelry even in a rough state.

The dark veining in many stones is matrix, the host rock the turquoise formed in. A fine network of it is called spiderweb matrix and is prized rather than penalized, especially in stones from the American Southwest. Pure, evenly colored sky blue material without matrix, historically associated with the mines near Nishapur in Iran, has long been the most valuable.

Hardness runs from about 5 to 6 on the Mohs scale, which is soft, and the stone is porous. Both facts drive everything else. Untreated turquoise absorbs oils, cosmetics and sweat, and over the years this darkens and greens it. That change is not damage in the eyes of everyone; in some traditions a stone that has taken on the color of its wearer's life is considered better, not worse.

Because of the porosity, a large share of commercial turquoise is stabilized, meaning it has been impregnated with resin to harden it and lock the color. Stabilized turquoise is real turquoise and is the sensible choice for a piece someone will wear daily. Reconstituted or dyed material, made from powder and binder, is a different matter and should be disclosed clearly.

What the December birthstone turquoise symbolizes

Turquoise has been treated as a protective stone almost everywhere it has been found. Persian riders set it into bridles in the belief it guarded against falls. Egyptian jewelry from the Sinai mines used it for protection in this life and the next. Across the Southwest of North America it has been, and remains, central to ceremonial and personal jewelry, associated with water, sky and wellbeing.

The name itself comes from the trade route rather than the source: European buyers received it through Turkish traders, and the French called it pierre turquoise, the Turkish stone.

Beyond protection, the most common traditional meanings are good fortune, friendship and healing, in the broad sense of restoring balance rather than any medical claim. Turquoise was often given rather than bought for oneself, and in several traditions a turquoise received as a gift carried more power than one purchased, which is a lovely idea to write on a card.

For a December birthday, that gives you a theme that has nothing to do with the holidays: protection and good wishes for the year ahead, given to someone about to head into whatever comes next.

Choosing a December birthstone turquoise gift when the holidays are in the way

December birthdays have the worst deal on the calendar. Gifts get combined, parties get skipped because everyone is already out five nights a week, and the birthday itself disappears into the general noise of the season.

The fix is deliberate separation, and it is worth stating out loud to the person: this is your birthday gift, your Christmas one is separate, and here is a card that is only about you.

For a daughter

The Dear Daughter interlocking hearts necklace is written for the season, so use it as the Christmas half of the pair rather than as the birthday gift. For the birthday itself, look through gifts for a daughter and pick a card that never mentions December at all.

For the wider family

The Memories We Share love knot necklace suits the relative you see once a year and think about far more often than that. Our Christmas gift range keeps the same structure: a pendant with a printed card, so the words are chosen rather than scribbled in a hurry on the day.

For someone who works through the holidays

The firefighter Christmas cross necklace is written for the people whose December is a shift rota rather than a holiday. Nurses, carers, emergency workers and retail staff all spend the season serving everyone else's, and a gift that acknowledges it lands hard.

What to write for a December birthday

The first rule is to leave the holidays out of the birthday card entirely. No festive greetings, no mention of the season, nothing that could have been written to the whole family. That single restriction does most of the work.

Write about the year she has had rather than the one ending on the calendar. A December birthday is a natural moment for a summary, and the honest version is better than the cheerful one: name the hard part, then name what she did about it.

If turquoise's meaning appeals, use the protection idea rather than the luck idea. "I want this year to be gentler with you" is a real wish. Luck is impersonal; protection sounds like someone is watching out.

Three sentences, handwritten, signed. Then keep the Christmas card for Christmas.

How to care for turquoise, which is softer than it looks

Turquoise is porous and soft, so the care rules are stricter than for any crystalline gem except opal and pearl.

Put it on after perfume, hairspray, lotion and makeup, and take it off before swimming, showering or cleaning. Untreated turquoise absorbs whatever it touches, and that absorption is what turns a sky blue stone green over the years. Stabilized turquoise resists this far better but is not immune.

Never use an ultrasonic cleaner, steam, or any chemical cleaner. Wipe it with a soft, slightly damp cloth and dry it immediately. Do not soak it.

Keep it out of prolonged direct sunlight and away from heat, both of which can dry and fade it. Store it separately in a soft pouch, because at 5 to 6 on the Mohs scale almost everything else in the box will scratch it. Our jewelry care tips cover the rest of the collection, and the printed card from a gift should be stored flat with the piece.

When to give it

Give a December birthday gift on the birthday, in a different room from the tree, wrapped in paper that is not holiday paper. Those three small decisions are what stop it becoming a Christmas present with a birthday label.

If the birthday falls in the last week of December, consider marking it in the summer instead, on a half birthday, which sounds like a joke until you watch someone realize they are getting a day that belongs only to them.

And if the gift is about protection for the year ahead, New Year is a legitimate second option. A gift given on the first quiet day of January, when the decorations are down and the year looks long, has a clarity that nothing given in December can match.

Questions buyers ask

Why is so much turquoise stabilized?

Natural turquoise is porous and soft, so it absorbs oils and can crumble in thin sections. Stabilizing it with resin hardens the stone and locks the color, which makes it practical for everyday jewelry. It is still genuine turquoise, and it should be disclosed.

Why does turquoise turn green?

Because it is porous. Skin oils, perfume, cosmetics and sweat are absorbed over time and shift the color toward green. Some wearers consider this a record of a life rather than a defect, but if you want to prevent it, put the piece on last and wipe it after wearing.

Can turquoise be worn every day?

With care, and preferably as a pendant or earrings rather than a ring. At 5 to 6 on the Mohs scale it scratches easily, and daily hand contact with lotions and cleaning products is what changes the color fastest.

What are December's other birthstones?

Tanzanite and zircon appear alongside turquoise on standard December lists, and some lists add blue topaz. December is well supplied, so a blue stone of some kind is always a correct choice for the month.