What Is the December Birthstone? Blue Topaz, Tanzanite & More
The December birthstone is blue topaz — alongside tanzanite, turquoise and zircon, giving December-born people four official stones, all in shades of blue. Blue topaz is the most widely worn thanks to its brilliance, durability (Mohs 8) and affordability; tanzanite is the rare modern addition, found only in Tanzania. This guide explains each stone, what they mean in tradition, and which zodiac signs share the month.
The Four December Birthstones Explained
- Blue topaz — natural topaz in sky, Swiss and London blue, its colour developed through standard irradiation and heat treatment. Hard-wearing at Mohs 8 and traditionally associated with clarity and calm.
- Tanzanite — violet-blue zoisite discovered in 1967 near the Merelani Hills, Tanzania, the world's only source. Added to the official birthstone list in 2002 and traditionally linked with new beginnings.
- Turquoise — the traditional December stone, worn since ancient Egypt and associated in folklore with protection and good fortune.
- Zircon — a brilliant natural gemstone (not cubic zirconia). Blue zircon was especially loved in Victorian jewellery, and Australian zircon crystals are the oldest known minerals on Earth.
What Colour Is the December Birthstone?
Blue, in almost every shade: the pale ice of sky blue topaz, the vivid pop of Swiss blue, the deep teal of London blue, tanzanite's violet-blue, turquoise's robin's-egg and zircon's electric sea-blue. If you're buying for someone born in December, you genuinely cannot go wrong with blue.
December Zodiac Signs: Sagittarius & Capricorn
December spans two star signs. Sagittarius (22 November – 21 December) is the optimistic archer, traditionally paired with both citrine and topaz — explore our Sagittarius jewellery collection. Capricorn (22 December – 19 January) begins in late December and is traditionally linked with garnet, January's stone. As always, zodiac associations are folklore rather than fact — but they make gift-choosing more fun.
The Meaning of the December Birthstone
In centuries of tradition, blue topaz has been associated with clarity, loyalty, calm and good fortune, while tanzanite's modern symbolism centres on transformation and fresh starts. These are belief-based meanings, not properties of the stones — but they're the stories that make a birthstone gift feel personal.
Shop December Birthstone Jewellery
Every Irosk piece is handcrafted in 925 sterling silver. Explore blue topaz rings, topaz earrings, topaz necklaces, topaz bracelets and rare tanzanite jewellery — or browse the complete December birthstone collection. For a deeper dive, read our blue topaz guide or discover December's birthstone and flower.
Frequently Asked Questions
What is the official December birthstone?
December has four recognised birthstones: blue topaz, tanzanite, turquoise and zircon. Blue topaz and tanzanite are the most popular in modern jewellery.
Is tanzanite or blue topaz better for December?
Blue topaz is harder (Mohs 8) and suits daily wear; tanzanite is rarer and more colour-shifting but softer (Mohs 6–7). Choose topaz for everyday pieces and tanzanite for occasion jewellery.
What zodiac signs are in December?
Sagittarius covers 1–21 December and Capricorn begins on 22 December.
About Irosk Australia
Irosk is an Australian jewellery brand specialising in handcrafted 925 sterling silver birthstone and gemstone jewellery. Founded by Ish and Lovneet in 2021 and based in Brisbane, Irosk creates timeless, meaningful pieces designed for gifting and everyday wear — each one crafted with care and accurately described so you always know exactly what you're getting. Your stone. Your story.