What Is My Birthstone?
December Birthstone: Turquoise, Tanzanite, Zircon
Turquoise, Tanzanite, Zircon
December has three modern birthstones, all in shades of blue: turquoise, tanzanite and zircon. Turquoise is the ancient choice, an opaque copper mineral mined for at least 5,000 years. Tanzanite, a violet-blue zoisite found only in one place on Earth near Mount Kilimanjaro, was added in 2002. Blue zircon is a brilliant natural gem often confused with, but unrelated to, synthetic cubic zirconia.
Turquoise's color runs from sky blue to green depending on copper and iron content, and the most valuable material is an even robin's-egg blue with no matrix, historically from Persia and the American Southwest.
Lapis lazuli and blue topaz also appear on December lists, making it the month with the widest choice of blue stones.
December birthstones at a glance
- Modern birthstones: Turquoise, Tanzanite, Zircon
- Traditional birthstones: Turquoise, Lapis Lazuli
- Alternates: Topaz
- Color: sky blue to blue-green
- Traditionally associated with protection, prosperity and good fortune
About Turquoise
Turquoise is a blue-green phosphate mineral prized for thousands of years. Persian turquoise is considered the finest quality.
| Type | Semi-Precious Stones |
|---|---|
| Chemical formula | CuAl6(PO4)4(OH)8·4H2O |
| Mohs hardness | 6 |
| Crystal system | triclinic |
| Luster | waxy |
| Streak | White to pale green |
| Cleavage | Good |
- One of the first gemstones ever mined, dating back to 6000 BCE
- The word 'turquoise' comes from French for 'Turkish stone'
- Native Americans consider it a sacred stone
How to tell real Turquoise at a glance
- Color: Blue, Blue-Green, Green. Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue.
- Luster: Waxy. Compare a fresh surface with glass and metal; this luster is softer than either.
- Transparency: Opaque. Hold a thin edge up to a bright light and note whether light passes through.
- Mohs hardness: 6. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will.
Other stones on this page
Frequently asked questions
What is the birthstone for December?
The modern December birthstone is Turquoise, Tanzanite, Zircon. The traditional stone is Lapis Lazuli. Topaz is also used.
What color is the December birthstone?
Turquoise is sky blue to blue-green.
Why does December have three birthstones?
Turquoise and lapis are the historic stones. Zircon was added in 1952 and tanzanite in 2002 to give December transparent, faceted options in blue.
How can I tell real turquoise from dyed howlite?
Dyed howlite shows color pooling in its veins and often turns a cotton swab blue with acetone. Real turquoise has irregular matrix, is slightly waxy and never bleeds dye.
