December is the only month that comes with four birthstones: tanzanite, turquoise, blue topaz, and zircon.

Tanzanite leans blue-violet, sometimes tipping into a deep, almost ink-like purple. Turquoise sits at the warmer end of blue, closer to the sky than the sea. Zircon is clear and vivid in a way that catches the light differently than any of the other three. And blue topaz actually comes in three different shades, from a light sky blue to a deep London blue. Different stones, same color family, and a kind of December uniform.

That's part of why December birthstone jewelry is such a popular gift this time of year. A birthstone piece already carries meaning on its own, and with so much choice, you can make it as personal as you want.

What is the December birthstone?

Tanzanite, turquoise, blue topaz, and zircon are the four stones officially recognized as December's birthstones in the United States today. Birthstones themselves go back quite a bit further than today. The tradition is often traced to the breastplate of Aaron in the Book of Exodus, a garment set with twelve gemstones representing the twelve tribes of Israel. The modern, standardized list most jewelers use wasn't settled until 1912, when the National Association of Jewelers sat down and assigned one stone to each month for the sake of consistency.

December's lineup evolved over time:

• Turquoise and zircon were both part of that original 1912 standard list, giving December a mix of ancient history and natural brilliance from the start.
• Blue topaz grew into a hugely popular commercial alternative throughout the late 20th century, offering an accessible, durable option in every shade of blue.
• Tanzanite joined the list in 2002 when the American Gem Trade Association (AGTA) added it, making it the first official addition to the national birthstone calendar in fifty years and one of the newest birthstones overall.

What ties all four together: color. Tanzanite, turquoise, blue topaz and zircon all sit somewhere in the blue family, whether that's a violet-leaning blue, a green-leaning blue, a soft sky blue, or a blue so clear it looks lit from within. December got a color, more than it got a single stone.

December birthstone meaning & symbolism

Each of December's four stones carries its own symbolism, and together they complement each other better than most birthstone months with multiple stones manage to.

Tanzanite is associated with transformation: insight, and that sense of seeing something clearly for the first time. It's a newer stone with an old kind of meaning attached to it.

Turquoise has the longest résumé of the four. Ancient Persians called it pirouzeh, meaning victory, and believed it offered protection against harm. Egyptians associated it with Hathor, goddess of love and joy, and used it in burial jewelry meant to protect the dead in the next life. Native American tribes across the Southwest (Navajo, Zuni, and Hopi among them) considered turquoise sacred, using it in ceremonies and treating it as a link between earth and sky.

Zircon's symbolism revolves around wisdom, honor, and prosperity. In medieval Europe, people believed it warded off evil spirits and helped its wearer sleep, which, fair, most of us could use a stone for that.

Blue topaz's meaning is the most practical of the four: honesty, clear communication, emotional balance. Less mystical than the others, maybe, but a stone for everyday steadiness.

What color is the December birthstone?

Tanzanite runs from a violet-blue to a deep, almost purple-blue, and the exact shade you see depends on where you're standing. That's because tanzanite is trichroic, meaning it shows three different colors (blue, violet, and a burgundy-adjacent tone) depending on the angle it's viewed from. Cutters orient the rough stone specifically to bring out the blue-violet that's most prized.

Turquoise ranges from a robin's-egg blue to a blue-green, and its value has almost as much to do with pattern as it does with color. Most turquoise carries a matrix (thin veining left behind from the rock it formed inside) and that matrix can raise or lower the price depending on taste. Cleaner stones with little to no matrix are traditionally the most valuable; stones with dramatic black or brown webbing have their own devoted following.

Blue zircon is the most saturated of the four, ranging from a bright sky blue to something closer to electric. Most of that color comes from heat-treating naturally brownish zircon, a standard and disclosed practice in the trade.

Blue topaz actually comes in three recognized shades, and they're different enough to be called different things. Sky blue is the palest, almost aquamarine. Swiss blue sits in the middle: bright, saturated, the shade most people picture. London blue is the deepest, a steely navy with a bit of gray underneath it, and generally the most valuable of the three.

Across all four stones, the same rule applies: deeper, more even saturation costs more, and origin matters.

The history of December birthstones

Turquoise's history is the longest of the four. Egyptians were mining it in the Sinai Peninsula as early as 3000 BCE, setting it into jewelry, amulets, and burial pieces (most famously the burial mask of Tutankhamun, inlaid with turquoise alongside lapis lazuli and carnelian). Persian craftsmen used it to decorate palace domes, believing its blue represented the heavens. Centuries later, and an ocean away, Native American tribes of the American Southwest developed their own independent reverence for the stone, using it in ceremony, trade, and jewelry that had nothing to do with Egypt or Persia and everything to do with their own traditions.

Tanzanite, by contrast, is barely sixty years old. The story usually told credits a prospector named Manuel de Souza, who came across a cluster of blue-violet crystals near Mount Kilimanjaro in 1967, though some accounts credit a Maasai herder with finding it first and bringing it to de Souza. Either way, the stone reached Tiffany & Co. within a year, and Tiffany did what Tiffany does: named it, marketed it, and launched a full tanzanite collection in 1968. It's rare, in the true sense of the word, to watch a gemstone travel from undiscovered to globally desired inside a single decade.

Blue topaz's history is a little of both: old mineral, new stone. Colorless topaz has been mined and worn for centuries, but the deep, consistent blue people associate with the name didn't really exist commercially until gem labs worked out how to irradiate and heat-treat colorless crystals into a stable, permanent color. That's why blue topaz can feel like the newest stone on this list even though topaz itself is anything but.

As for zircon, its story as a birthstone is nearly as old as modern record-keeping itself. It officially joined December on the original 1912 jewelers' list. Long before that, medieval travelers wore zircon as a portable shield, believing the bright gem could ward off evil spirits, bring prosperity, and grant restful sleep on long journeys.

December birthstone facts

Tanzanite sits at 6.5-7 on the Mohs hardness scale: hard enough for regular wear, though it should still avoid sharp knocks and skip the ultrasonic cleaner. It's also found in exactly one place on Earth: a narrow strip of land near Mount Kilimanjaro, Tanzania, and nowhere else that's ever been documented. Because that source is finite and increasingly hard to access, tanzanite is often described as rarer than diamond, which is an odd thing to say about a stone most people have never held.

Turquoise measures 5-6 on the Mohs scale, softer than the other three, and porous, meaning it can absorb oils, lotion, and perfume, which changes its color over time. That's not damage, exactly. It's more that turquoise keeps a record of how it's worn.

Blue zircon comes in around 6-7.5, the widest range of the four, and its high refractive index gives it a natural brilliance that rivals stones twice its price. And blue topaz is the hardest of the four at 8 on the Mohs scale (harder than quartz, harder than amethyst, close to sapphire).

One thing worth clearing up: zircon and cubic zirconia are not related. Zircon is a natural mineral that's been mined and worn for centuries. Cubic zirconia is a lab-made diamond simulant that happens to share part of its name.

December birthstone jewelry ideas

Looking for an heirloom piece? The Dragonfly Necklace is a unique piece that pairs actual tanzanite with London blue topaz, which is a nice option if you want the rarer stone represented. On the turquoise side, the Oval Sea Goddess Pendant is two-sided (a sea goddess on natural turquoise, a sunrise over the ocean on the reverse), the Seashell Turquoise Pendant leans coastal and sculptural, and the Mandala Turquoise Pendant sets turquoise into a mandala with a single pink tourmaline center.

That personalization is really where December birthstone jewelry becomes a very special gift. Our birthstone rings, birthstone studs, and birthstone charm necklace all let you choose the stone per person, with a hand-selected blue topaz to represent December.

How to care for December birthstone jewelry

• Tanzanite: clean with warm, soapy water and a soft brush only. Skip the ultrasonic and steam cleaners entirely.
• Turquoise: keep it away from water, lotion, perfume, and household chemicals. A dry, soft cloth is really all it needs. This stone is porous, so prevention matters more than cleaning ever will.
• Blue zircon: mild soap and warm water with a soft brush, the same gentle routine as tanzanite. It's harder than turquoise but more brittle than it looks, so a soft touch still applies.
• Blue topaz: a soft cloth and warm, soapy water is really all it takes. Skip the ultrasonic cleaner here too.

Store all four separately, in a lined box or individual pouch, away from anything that could scratch or be scratched. And the usual rule holds here too: remove jewelry before the gym, the pool, or the spa. Blue topaz is the most forgiving of the four for daily wear, hardness-wise, so long as it avoids a hard, direct knock.

December birthstone frequently asked questions

What is the December birthstone?

December has four recognized birthstones: tanzanite, turquoise, blue zircon, and blue topaz. Blue topaz is the one most widely used in modern jewelry, including our own December birthstone pieces, since it's durable and easy to find at almost any budget.

Why does December have four birthstones?

Birthstone lists have evolved over time. When the modern standard was established in 1912, turquoise and zircon were assigned to December. Blue topaz grew in popularity as a durable alternative over the following decades, and tanzanite was officially added to the AGTA list in 2002 to bring a rare blue-violet option into the mix.

What color is the December birthstone?

Tanzanite runs blue-violet to deep purple-blue, turquoise ranges from robin's-egg blue to blue-green, blue zircon leans toward sky blue or electric blue, and blue topaz spans three shades of its own: pale sky blue, vivid Swiss blue, and deep London blue.

What is the difference between zircon and cubic zirconia?

They're unrelated despite the similar name. Zircon is a natural mineral that's been mined and worn for centuries. Cubic zirconia is a lab-made material created as a diamond alternative.

Can December birthstones be worn every day?

Blue topaz is the sturdiest of the four and the most common choice for daily wear. Blue zircon holds up well too. Turquoise and tanzanite can be worn daily as well, but they're softer and more porous or brittle, respectively, so they do better with a little more care (removed before the gym, the pool, or a long day of manual work).

What zodiac signs are associated with December birthstones?

December has two zodiac signs: Sagittarius (November 22–December 21) and Capricorn (December 22–January 19).