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December Birthstone

Jared James, co-founder of LILY DIA

By Jared James · Last updated 17 May 2026

Quick answer

December has three modern birthstones: tanzanite, zircon and turquoise. Tanzanite is a rich violet-blue zoisite, found only in Tanzania, at 6 to 7 Mohs. Zircon is a natural mineral with diamond-like brilliance, often seen as a vivid blue, at 6 to 7.5 Mohs. Turquoise is the oldest of the three, a sky-blue to green opaque stone at 5 to 6 Mohs. All three need careful handling compared with a diamond or sapphire.

December stones at a glance

December birthstones compared on colour, hardness and classification
StoneColourHardnessList
TanzaniteViolet-blue, shifting toward blue or violet by viewing angle6 to 7 MohsModern
ZirconBlue, colourless, yellow, green, red6 to 7.5 MohsModern
TurquoiseSky blue to green, sometimes with matrix patterns5 to 6 MohsModern

Modern vs traditional

Turquoise and zircon are the older traditional December stones. Tanzanite was added in 2002, decades after its discovery near Mount Kilimanjaro in 1967. Lapis lazuli also appears on some older traditional lists. All three modern stones are recognised today.

Colour and meaning

Tanzanite shifts between blue and violet depending on the viewing angle and the light source, which is one reason it has become so popular since its discovery in 1967. Zircon has high brilliance and dispersion, second only to diamond, and the blue variety reads close to aquamarine but more saturated. Turquoise has been treasured for over 5,000 years, from Egyptian tombs to Navajo silver work, and reads more grounded and earthy than the other two December stones.

Durability and best uses

None of the December stones is as hard as sapphire or diamond. Tanzanite at 6 to 7 Mohs is sensitive to temperature changes and needs a protected setting for a ring. Zircon at 6 to 7.5 Mohs is brittle, so its facet edges can chip with hard wear. Turquoise at 5 to 6 Mohs is the softest and porous, and is far more comfortable in earrings and pendants than in an everyday ring.

History and lore

Tanzanite was discovered after a 1967 grass fire near Mount Kilimanjaro that exposed crystals in the soil. Tiffany & Co. introduced the stone commercially and named it after Tanzania. Zircon has been used in jewellery since the Middle Ages and was once a primary diamond imitation before cubic zirconia was developed. Turquoise has been mined for over 5,000 years, set into Egyptian gold, Persian palace walls and Navajo silver, and remains a strong cultural stone in the American Southwest.

Gift ideas

A tanzanite pendant in white gold reads modern, dressy and distinctive. Blue zircon makes vivid earrings and rings at an accessible price, and is a sensible choice if the December birthday person wants brilliance without a diamond budget. Turquoise reads relaxed and bohemian, and works in cuffs, pendants and statement necklaces in either silver or yellow gold.

Care

Tanzanite is sensitive to sudden temperature changes and should be cleaned with warm soapy water by hand only, never ultrasonic or steam. Zircon is safe in warm soapy water but skip ultrasonic cleaning because of brittleness. Turquoise is porous: keep it away from perfume, hairspray, lotions and even extended water contact, and clean only with a dry soft cloth.

Zodiac and anniversary

Zodiac: Sagittarius (until 21 December) and Capricorn (from 22 December).

Anniversary: Tanzanite is associated with the 24th wedding anniversary. Turquoise is the traditional 11th.

Designing a custom piece

Start a custom design

Birthstone rings and pendants are usually made to order. Tell us the stone, the wearer and the piece you have in mind, and we will help you compare options before we draw anything up.

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Frequently asked questions

What is the birthstone for December?
December has three modern birthstones: tanzanite, zircon and turquoise. Turquoise and zircon are the older traditional stones, and tanzanite was added in 2002 after its 1967 discovery.
Is tanzanite hard enough for an engagement ring?
It can be used, but it needs care. Tanzanite is 6 to 7 on the Mohs scale and is sensitive to temperature changes, so a protected setting is strongly preferred and ultrasonic cleaning should be avoided.
Is zircon the same as cubic zirconia?
No. Zircon is a natural mineral that has been used in jewellery for centuries. Cubic zirconia is a lab-made diamond imitation made of a different material. The names are confusingly similar but the stones are not the same.
Is turquoise rare?
Genuine high-grade turquoise without resin stabilisation is uncommon, particularly the Persian and Sleeping Beauty material that was once standard. Most turquoise in commercial jewellery today is stabilised to harden the surface, which is disclosed and accepted.

Still deciding

Talk through the december birthstone with us

Send the wearer, the piece you have in mind and a sense of budget, and we will help you compare stones and settings before we draw anything up.

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