2027 Forecast

December · Blue to blue-violet

December birthstone: Turquoise

The December birthstones are Turquoise, Zircon and Tanzanite — the month carries 3 official modern stones, which is why sources disagree about it. The traditional list keeps only Turquoise; Zircon and Tanzanite were added later.

1912 jewelers’ list
Turquoise or lapis-lazuli · Kansas City
Older lists
Ruby · 6 of 8 Kunz’s tally of 8 old lists
December births
8.35% #6 of 12 months, US 2000–2014

Kunz 1913; US births 2000–2014.

The months either side, and the same month in flowers: November birthstone, January birthstone and December birth flower.

All twelve months, modern and traditional lists in one table: birthstones by month.

December Birthstones: Turquoise, Zircon and Tanzanite
Modern birthstone Turquoise, Zircon, Tanzanite
Traditional birthstone Turquoise
Color Blue to blue-violet
Birth flower Narcissus and Holly
Zodiac signs Sagittarius, Capricorn
Hardness (Mohs) 5–6

Tanzanite joined in 2002 — the first addition since the 1952 revision, and the only birthstone found in one place on Earth.

December stones in detail

Turquoise

Composition Hydrated copper aluminum phosphate (CuAl₆(PO₄)₄(OH)₈·4H₂O)
Hardness · Crystal system 5–6 · Triclinic
Mined in Iran, USA (Arizona, Nevada), China, Egypt

Porous enough to absorb oils and change color over years of wear — some cultures read that shift as meaningful.

Traditionally the classic travel-protection stone, also linked to plain speech.

Care. Wipe with a dry or barely damp cloth. Never soak, never ultrasonic — turquoise is porous and absorbs whatever it touches.

Spotting a fake. Most affordable turquoise is resin-stabilized, which is normal. Dyed howlite is the outright fake: scratch an inconspicuous spot and dyed material shows white beneath.

Zircon

Composition Zirconium silicate (ZrSiO₄)
Hardness · Crystal system 6–7.5 · Tetragonal
Mined in Cambodia, Myanmar, Sri Lanka, Australia, Tanzania

Not to be confused with cubic zirconia, a synthetic diamond simulant. Natural zircon has high dispersion and real geological age.

Traditionally associated with grounding and restful sleep.

Care. Warm soapy water. Avoid ultrasonic — zircon is brittle and chips at facet edges.

Spotting a fake. Not to be confused with cubic zirconia, which is synthetic and unrelated. Natural zircon shows strong doubling of the back facets viewed through the table.

Tanzanite

Composition Calcium aluminum silicate (Ca₂Al₃(SiO₄)₃(OH)) — blue zoisite
Hardness · Crystal system 6–7 · Orthorhombic
Mined in Tanzania (Merelani Hills — the only source on Earth)

Mined in a strip of land roughly seven kilometres long. At current rates the deposit is expected to run out within decades.

Traditionally linked to perspective shifts and seeing a situation from above.

Care. Warm soapy water and a soft brush. No ultrasonic, no steam — tanzanite is sensitive to sudden temperature change.

Spotting a fake. Effectively all tanzanite is heat-treated to produce the blue; unheated material is brown and rare. Coated imitations exist and need a lab to separate.

The story of the December stones

Turquoise is one of the oldest gems in use: the ancient Egyptians mined it in Sinai, and its name comes from the French for "Turkish", since it reached Europe through Turkish trade. Zircon is old in a different sense — zircon crystals from the Jack Hills in Western Australia, over 4.4 billion years old, are the most ancient pieces of the Earth known. Tanzanite, discovered in 1967, was named and launched by Tiffany & Co. the following year.

Choosing a December stone

In turquoise, sky blue is the classic color and the dark veining of its host rock, called matrix, is a matter of taste — a fine "spiderweb" pattern is prized. Most blue zircon starts out brown and is heated to its color, which is standard. In tanzanite, the deeper the violet-blue the higher the price, and larger stones show the color more intensely.

Primary source

December in George Kunz’s Curious Lore of Precious Stones (1913)

The verse for December
“If cold December give you birth— The month of snow and ice and mirth— Place on your hand a ruby true; Success will bless whate’er you do.”
Kunz on the 1912 list
“it will be noted that the ruby is transferred from December to July, changing places with the turquoise, which became the gem of December.”
George Frederick Kunz, The Curious Lore of Precious Stones (Philadelphia and London: J. B. Lippincott, 1913), chapter IX, “Birth-Stones” — read the original text. Kunz’s traditional stone for December is ruby, and the jewelers’ list adopted in Kansas City in 1912 gives turquoise (alternative: lapis-lazuli). In his tally of eight older lists, December went to ruby in 6 of them, turquoise in 2, chrysoprase in 1, bloodstone in 1 — some lists give a month two stones. Which lists Kunz compared, and where the verses come from →

December birth flowers

Narcissus

Traditionally signifies the wish for others to stay as they are.

Holly

Traditionally signifies defense and domestic happiness.

More on December birth flowers →

If you go by zodiac sign instead

December spans two signs — Sagittarius and Capricorn — and the zodiac stone list does not match the monthly one. Which applies to you depends on the day, not just the month.

Sagittarius stones · Capricorn stones

Questions about the December birthstone

What is the birthstone for December?

The modern December birthstones are Turquoise, Zircon and Tanzanite.

What color is the December birthstone?

Blue to blue-violet.

What is the December birth flower?

Narcissus and Holly; the narcissus traditionally signifies the wish for others to stay as they are.

Is Turquoise hard enough to wear every day?

Turquoise rates 5–6 on the Mohs scale. It can be worn often, with care around skin oils, soap and cosmetics, which it absorbs.

What zodiac signs fall in December?

Sagittarius and Capricorn.

Other months

January February March April May June July August September October November

Measured against our reference of 43 stones

The December stones, by hardness

Turquoise · modern and traditional Mohs 5–6 · -0.85 vs average · wear with care
Zircon · modern Mohs 6–7.5 · +0.4 vs average · wear with care
Tanzanite · modern Mohs 6–7 · +0.15 vs average · wear with care
Lapis Lazuli · alternative Mohs 5–6 · -0.85 vs average · wear with care
Average across all 43 stones Mohs 6.35
Modern and traditional Turquoise in both
December birthstones on the Mohs hardness scale
December birthstones on the Mohs hardness scaleMohs scale from talc (1) to diamond (10) with the December birthstones marked: Turquoise 5–6, Zircon 6–7.5, Tanzanite 6–7.Turquoise: Mohs 5–6Turquoise 5–6Zircon: Mohs 6–7.5Zircon 6–7.5Tanzanite: Mohs 6–7Tanzanite 6–7Garnet: Mohs 6.5–7.5Amethyst: Mohs 7Citrine: Mohs 7Rose Quartz: Mohs 7Clear Quartz: Mohs 7Smoky Quartz: Mohs 7Aquamarine: Mohs 7.5–8Emerald: Mohs 7.5–8Bloodstone: Mohs 6.5–7Peridot: Mohs 6.5–7Sardonyx: Mohs 6.5–7Zircon: Mohs 6–7.5Carnelian: Mohs 6.5–7Onyx: Mohs 6.5–7Agate: Mohs 6.5–7Tiger's Eye: Mohs 6.5–7Aventurine: Mohs 6.5–7Diamond: Mohs 10Pearl: Mohs 2.5–4.5Alexandrite: Mohs 8.5Moonstone: Mohs 6–6.5Labradorite: Mohs 6–6.5Pyrite: Mohs 6–6.5Ruby: Mohs 9Sapphire: Mohs 9Spinel: Mohs 8Topaz: Mohs 8Opal: Mohs 5.5–6.5Rhodonite: Mohs 5.5–6.5Tourmaline: Mohs 7–7.5Turquoise: Mohs 5–6Lapis Lazuli: Mohs 5–6Hematite: Mohs 5–6Tanzanite: Mohs 6–7Jade: Mohs 6–7Obsidian: Mohs 5–5.5Malachite: Mohs 3.5–4Amber: Mohs 2–2.5Selenite: Mohs 2Fluorite: Mohs 4Sodalite: Mohs 5.5–6Kyanite: Mohs 4.5–7Lepidolite: Mohs 2.5–31Talc2Gypsum3Calcite4Fluorite5Apatite6Orthoclase7Quartz8Topaz9Corundum10Diamondfingernail 2.5window glass 5.5household dust (quartz) 7Source: Mohs scale minerals · ranges from our 43-stone referenceastrohot.com
December birthstones on the Mohs hardness scaleMohs scale from talc (1) to diamond (10) with the December birthstones marked: Turquoise 5–6, Zircon 6–7.5, Tanzanite 6–7.Turquoise: Mohs 5–6Turquoise 5–6Zircon: Mohs 6–7.5Zircon 6–7.5Tanzanite: Mohs 6–7Tanzanite 6–71Talc2Gypsum3Calcite4Fluorite5Apatite6Orthoclase7Quartz8Topaz9Corundum10Diamondfingernail 2.5glass 5.5dust 7Source: Mohs scale minerals · ranges from our 43-stone referenceastrohot.com

December on the scale: Turquoise 5–6, Zircon 6–7.5, Tanzanite 6–7. Of the twelve months’ first-listed modern stones, Turquoise is the 11th hardest.

Turquoise: Hydrated copper aluminum phosphate (CuAl₆(PO₄)₄(OH)₈·4H₂O). Crystal system Triclinic. Below Mohs 7 it is scratched by ordinary airborne dust — quartz sits at 7.

Who this month covers

Days in December 31
Sagittarius · December 1–21 69.7% of December births
Capricorn · December 22–31 30.3% of December births

Sagittarius takes the larger part of December, 21 days against 10 for Capricorn, which in US births for 2000–2014 came to 69.7% of the month. Exact sign dates →

Sources

  1. George Frederick Kunz, The Curious Lore of Precious Stones (Philadelphia and London: J. B. Lippincott, 1913), chapter IX, “Birth-Stones”

Statements of fact on this page were checked against these sources in October 2026. How we choose and check sources: editorial policy.

Cite this page

AstroHot. “December Birthstones: Turquoise, Zircon and Tanzanite.” Accessed October 28, 2026. https://astrohot.com/birthstones/by-month/december/

For Wikipedia {{cite web |title=December Birthstones: Turquoise, Zircon and Tanzanite |url=https://astrohot.com/birthstones/by-month/december/ |website=AstroHot |access-date=2026-10-28}}