December Birthstones: A Trio of Jewels for the Year’s End

December is one of two months with three birthstones: turquoise, tanzanite, and zircon, particularly blue zircon.

The month of December gets its name from the Latin decem, meaning “ten,” because it used to be the tenth month.

Modern December celebrations include Winter Solstice, Christmas, Hanukkah, Kwanzaa, and New Year’s Eve.

The month symbolizes change, camaraderie, and warm reunions during chillier days.

Today, we’ll discuss the symbolism, history, properties, and value of the three December birthstones: turquoise, tanzanite, and zircon.

december birthstones turquoise tanzanite and zirconCheck out our video on December Birthstones on Youtube!

Historical & Cultural Significance of December Birthstones

December has three birthstones: turquoise, tanzanite, and zircon.

But why does December have 3 birthstones? Birthstone lists have changed, and December’s gemstones have arguably changed the most.

The earliest birthstones, inspired by Biblical gemstone lists, designated ruby for December.

The modern birthstone list timeline for December stones:

  • 1870: Turquoise; From Tiffany & Co’s “Gregorian Birthstone Poems” pamphlet

  • 1912: Turquoise (primary), lapis lazuli (alternative); From National Association of Jewellers (now Jewellers of America)

  • 1952: Zircon added to 1912 list; From Jewelry Industry Council of America

  • 2002: Tanzanite added

So, what is the real birthstone for December? Turquoise has been listed most consistently, but each birthstone has its own lore and appeal.

ancient egyptian turquoise and gold pendantPictured above: Gold and turquoise Egyptian pendant, 21st Dynasty 1069-713 BC; Displayed at Cleveland Museum of Art in Ohio, USA | Image credit: Daderot, Public domain

Turquoise’s Revered Status in Ancient Civilizations

Turquoise was among the earliest gems. In fact, a 5500-BC Egyptian turquoise bracelet is among the oldest jewelry.

Ancient Egyptians mined turquoise — called mefkat for “joy” — since at least 3000 BC. They wore it for protection and status, associating it with sky & motherhood goddess Hathor.

Ancient Persian turquoise — called pērōzah, meaning “victory” — was purer, so they believed it was heavenly. They’d set turquoise in turbans, weapons, and mosques.

Ancient Greeks and Romans called turquoise callais and made turquoise beads, necklaces, and rings. Another early name was the Aztec chalchihuitl.

Aztecs viewed turquoise as sacred, passed down from the deity Quetzalcoatl. They believed it embodied fire, burying rulers with turquoise in their mouth..

Similarly, Native American tribes prized turquoise as ceremonial items, talismans, and currency. The Apache tribe attached turquoise to bows to ensure accurate aim.

Turkish travelers introduced Persian turquoise to medieval Europe, which became popular after the 14th century and more so in the Victorian Era. The name “turquoise” dates back to the 1300s, derived from the French turquois, meaning “Turkish.”

queen of kilimanjaro tanzanite tiaraPictured above: The Queen of Kilimanjaro, "whe world's largest faceted tanzanite", set in a tiara adorned with diamonds and tsavorite garnets; From a display in the Mineral Gallery in the Royal Ontario Museum in Toronto | Image credit: Mala C, Flickr, CC-BY-SA-2.0

Tanzanite’s Modern Discovery & Historical Connections

Tanzanite’s history is much shorter but no less interesting. Many gemologists cite tanzanite as the most significant gemstone discovery since alexandrite in 1834.

This December birthstone was discovered in Tanzania in 1967 by Indian tailor and prospector Manuel de Souza.

De Souza believed it was olivine; others considered dumortierite or cordierite. He called on American geologist Dr. John Saul. Saul tasked his father, Hyman Saul, with taking specimens back to New York. Saul had the Gemological Institute of America (GIA) analyze them. They found that it was a new vanadium-bearing zoisite variety.

Hyman and Saul worked with Tiffany & Co gem buyer Henry Platt to develop a marketing plan. Platt coined the name “tanzanite.”

17th to 19th century zircon amulet from nepalPictured above: Nepal amulet case with Vishnu Riding Garuda, featuring gold, rubies, sapphires, emeralds, pearls, zircon, coral, lapis lazuli, and turquoise; Dated 17th–19th century; Displayed at Metropolitan Museum of Art | Image credit: Met Museum, Public domain

Zircon’s Fascinating History

Zircon is not only the oldest December birthstone, but it’s also the oldest known mineral on Earth based on Australian specimens dated over 4.4 billion years old!

The name “zircon” may come from the Arabic zarkun, meaning “vermillion,” or the Persian zargun, meaning “gold-colored.”

Warm-colored zircons were called hyacinth or jacinth, after the hyacinthus flower, by ancient Greeks. Another plant connected to zircon is the Kalpa Tree, a wish-granting tree in ancient Indian mythology said to bear green zircon leaves.

There are zircon references in the Bible, but translations vary — the Hebrew shoham likely meant chrysolite and ligyrion could be zircon, amber, or tourmaline.

The name “zircon” came in 1783, but the earliest names were lyncurion (Theophrastus around 300 BC) and chrysolithos (Pliny the Elder in 37 AD).

Zircon gemstone mining goes back to the 1st century AD if not earlier. In Italy and Greece, zircon uses go back to 500 AD.

White zircons being sold as diamond substitutes goes back to when faceting began in the 1300s. By the Victorian era, blue zircon jewelry was favored in mourning jewelry and English estate jewelry.

Geological Marvel: The Formation of Turquoise, Tanzanite, and Zircon

Next, we’ll look at each December birthstone’s formation and mineralogy.

tumbled turquoise beaded necklacePictured above: Tumbled turquoise beaded necklace

Turquoise Properties

Turquoise is a hydrated copper aluminum phosphate that’s porous, making its Mohs hardness oscillate between 5 to 6. Almost all turquoise is microcrystalline, like chalcedony.

The December birthstone forms as a secondary mineral when copper-rich water alters phosphorus- and aluminum-bearing minerals.

Turquoise is often found mixed with copper minerals like:

China and the US are turquoise’s top sources.

violet blue tanzanite crystal roughPictured above: Rough tanzanite crystal

Tanzanite Properties

Tanzanite is a variety of the calcium aluminum silicate zoisite, with a hardness of 6 to 7. Tanzanite is also the rarest birthstone for December, only found in a small area near the Mererani Hills.

Geologists estimate tanzanite formed 585 million years ago. The formation involved tectonic activity, heat, and Tanzania’s unique underground environment.

reddish brown zircon crystal roughPictured above: Rough red zircon crystals

Zircon Properties

Zircon is a natural zirconium silicate mineral often confused with the zirconium dioxide cubic zirconia, which is usually synthetic.

Among the December birthstones, zircon has the highest Mohs hardness at 7.5. Another unique trait? Containing traces of radioactive substances like uranium. This allows zircon’s properties to change over time and helps geochronologists study ancient geologic events using zircon.

Gem-quality zircons mostly come from Sri Lanka, Vietnam, Cambodia, and Myanmar.

robins egg blue turquoise cabochonPictured above: Robin's egg blue turquoise cabochon

Turquoise's Timeless Charm: Unveiling the Sky Stone

Color is the primary feature of turquoise. The December birthstone’s color can be turquoise, blue, green, yellowish-green, and even yellow.

Blues are from copper in the mineral’s formula. Greens come from chromium or vanadium impurities. Yellows come from iron impurities. Rarely, strontium impurities create purple undertones.

You’ll often see colored remnants of the host rock where turquoise formed, present as veins or patches called a “matrix.” The patterns can also be other minerals, like dark limonite webbing or golden pyrite flecks.

Certain sources produce distinct types of turquoise, such as:

  • Persian-Grade: Iran; Robin’s egg blue, no visible matrix

  • Sinai or “Egyptian”: Egypt; Usually greener, more translucent

  • Lynch Station: Virginia; Only source of transparent turquoise

  • Sleeping Beauty: Top American turquoise mine in Arizona; Solid sky blue to deep blue, little to no visible matrix

  • Kingman: Arizona; High-quality usually medium blue with black “water web” or “spiderweb” matrix

  • Bisbee: Arizona; Top-quality royal blue with brownish-red matrix

  • Sonoran Gold: Mexico; High-quality baby blue & lime green with yellow web matrix

  • Mohave: Arizona; Mosaicked with vivid purple, pink, blue, green, and red with bronze veining

Additionally, “turquoise” is sometimes a misnomer:

  • White Buffalo Turquoise: Gray, white, or dyed dolomite

  • African Turquoise: Teal, spotted jasper

  • Bone Turquoise / Occidental Turquoise: Fossil bone containing blue apatite

  • Kallait / Callais / Turquenite: Usually dyed howlite or magnesite

How does tanzanite’s color compare?

deep blue tanzanite faceted gemstonePictured above: Faceted tanzanite

Tanzanite's Mesmerizing Blue and Violet Beauty

Tanzanite’s color ranges from blue to purple, usually bluish-violet. Cool lighting will emphasize blues while warmer lighting brings out purples.

The December birthstone’s pleochroism is notable, shifting hues at different angles. Natural tanzanite can shift from violet to blue to yellow-green, brown, or green. Heat treatments cause only blue-to-violet shifts. Rarely, tanzanite is also color-changing.

Vanadium impurities that are heated (naturally or artificially) cause tanzanite’s colors.

faceted blue zircon gemstonePictured above: Faceted blue zircon

Zircon's Colorful Spectrum and Brilliance

Unlike turquoise and tanzanite, zircon December birthstones are more varied. The most popular color, however, is blue zircon.

Zircon’s gemstone colors and causes:

  • Blue: Usually greenish undertones; Almost always heat-treated; Trade names “starlite” or “stremlite”

  • Green: Incredibly rare; Usually brownish, bright green best; May be heat-treated to lighter shade; Trade name “beccarite”

  • “Gold” (Yellow to Orange): More affordable; Heated to be golden-yellow; Trade names “jargon” for light yellow and “melichrysos”

  • Red: Range in shades, usually reddish-brown; Trade name “hyacinth/jacinth” for reddish-brown & transparent

  • Purple: Caused by natural irradiation, lightened by sunlight and heat

  • Colorless / White: Little to no impurities (natural) or heat-treated colored zircons; Affordable alternative to diamond

  • Brown to Black: Most common natural color; Caused by iron oxide impurities

Radioactive elements in zircons can cause decay (metamictization) over time, changing their crystalline structure, colors, and other properties.

“Low zircon” is the oldest and most changed, usually cloudy and orange, yellow, green, or brownish-green. “High zircon” is the least changed and usually blue, colorless, or brownish-orange. Jewelry usually contains high zircon.

Color is just one part of the December birthstones’ grading.

Evaluating Quality: Turquoise, Tanzanite, and Zircon Characteristics

Gemstone quality is typically graded on color, cut, clarity, carat weight, and treatments.

Turquoise is a bit unique, graded on color, matrix, and texture. Dense textures have better polish luster; coarser textures have worse polish luster.

Color

Turquoise: The most valuable turquoise color is bright “robin’s egg” or “sky” blue with even distribution and no undertones. Green or greenish-blue turquoise is more affordable.

Medium-dark tones are the most valuable, as medium tones bring out turquoise’s vibrance best. Darker tones are usually more dull-looking.

Color-zoning usually lowers value, but one exception is the rare “bird’s eye” pattern.

Tanzanite: Tanzanite can be purple to blue. The most valuable colors are vibrant pure blue, but bright purplish-blue and violet-blue are also sought-after. The best tone is 75 to 85 percent. Strong pleochroism or color-changes are value boosters.

Zircon: Despite the range of zircon colors, the priciest and most popular is blue. Browns and reddish-browns are common, while vivid greens and reds are more valuable.

blue zircon december birthstone ringPictured above: Blue zircon ring with cubic zirconia accent stones

Cut

Turquoise: Most turquoise becomes cabochons. Inlay, carvings, or beads are also common.

Tanzanite: Many gem cutters prioritize retaining tanzanite’s weight in faceted cuts, so the resulting gems are usually more purple than blue. Common shapes are cushion and oval cuts.

Zircon: Faceted zircons are usually cut to maximize their luster, brilliance, and dispersion. Challenges include avoiding facet doubling (high birefringence) and chipping. Common shapes are brilliant rounds, ovals, step, or mixed cuts.

Cat’s eye zircons or tanzanites must be cut as cabochons.

Clarity, Transparency & Matrix

Clarity describes the degree of visible inclusions, which lowers transparency and value. Inclusions that cause chatoyancy, rare “cat’s eye” tanzanites and zircons, are exceptions.

Turquoise: Turquoise is typically opaque, so rare transparent to translucent specimens are pricier. Top-value turquoise birthstones have no visible matrix, but some matrix patterns like dark “spider-webs” are sought-after.

Tanzanite: Tanzanites have Type I clarity, so visible inclusions are uncommon and will lower value. Fractures can lower durability and value.

Zircon: Zircons have Type II clarity, so minor visible inclusions are expected outside of high-quality specimens. Untreated zircons may look cloudy.

tibetan spiderweb turquoise cabochonPictured above: Untreated Tibetan turquoise cabochon with spider-web pattern

Carat Weight

Turquoise: Turquoise birthstones come in various sizes. Larger specimens often have more apparent matrices, so big, matrix-free turquoise specimens are pricier.

Tanzanite: Tanzanite is available in various sizes, but price-per-carat jumps for gems over 1 carat and 3 carats. Oddly, tanzanites usually have better coloring in larger sizes.

Zircon: Size ranges vary by zircon’s color. Rarer colors like purple and red are smallest, yellow and orange go up to 5 carats, while blue and green go up to 10 carats. Larger size often means lower quality.

Treatments

Turquoise: Treatments for turquoise are often done to enhance their color, durability, and/or shine. Oil and wax coatings are most common. Other turquoise treatments include dyeing, soaking (Zachery treatment), or stabilizing the birthstone.

Tanzanite: Almost all tanzanite gems are heat-treated. A less desirable, rarer treatment is chemical coating.

Zircon: Heat treatments for zircon are routine and stable. Heating can make “low” zircon less metamict, improve clarity, or alter coloring. Most often, brown zircons are heated to become blue. Heat can also create colorless, yellow, light green, red, or golden zircons.

floral tanzanite carvingPictured above: Tanzanite carving

December Birthstones’ Meanings

The stone color of December is blue, so all December birthstones have the soothing and harmonizing properties of blue gemstones. But each birthstone has unique mystical qualities!

Turquoise Meanings

Many ancient societies believed turquoise was protective, including Persians, Apaches, and Aztecs. Other interpretations said turquoise symbolized heaven, purification, and hope.

Spiritually, Tibetan Buddhists wear malas (meditation beads) with turquoise representing spirituality and good luck.

Crystal healers recommend turquoise for treating inflammation, deflecting negativity, and promoting friendship.

Tanzanite Meanings

Tanzanite’s meaning largely revolves around transformation and communication. This December birthstone is believed to help you communicate wisely with compassion, especially in relationship disputes.

This healing stone is nicknamed the “Stone of Transformation” and “Stone of Magic.”

Spiritually, tanzanite is a third eye or crown chakra stone, boosting intuition and spiritual awareness.

Zircon Meanings

Historically, zircon was believed to grant good luck, better sleep, and protection during medieval times. Today, zircon symbolizes success, wisdom, and positivity.

The Greek myth of Hyacinth symbolizes rebirth, attaching this meaning to zircon’s “hyacinth” moniker. White zircon is seen as symbolic of purity, while yellow zircon is nicknamed the “Stone of Prosperity.”

blue topaz earrings - alternative december birthstonePictured above: Blue topaz earrings with white accent diamonds

Alternative December Birthstones

Not even three semi-precious gems fully cover December birthstones. Besides the historical lapis lazuli, many consider blue topaz a December birthstone.

Astrologically, Sagittarius signs fall before the 21st while Capricorn falls after. Sagittarius birthstones include amethyst, beryl, and lapis lazuli.

What is the birthstone for Capricorn? Beneficial Capricorn stones include iolite, corundum, and black tourmaline.

Personalized December Birthstone Gifts

Do you have a December-born loved one? Then December birthstone jewelry is a great gift that’s thoughtful and personalized!

Once you know their favorite birthstone, you can opt for a minimalist December birthstone ring or a customized December birthstone necklace that includes your own birthstone. You can even incorporate the daffodil (narcissus) birth flower into the design!

light blue tanzanite december birthstone ringPictured above: Faceted tanzanite ring

Celebrate the Best Winter Holiday With December Birthstones!

Being born around the holidays can be a drag, but having beautiful birthstones makes the dark days brighter. Do you love southwestern turquoise, modern tanzanite, or diverse zircon? The best birthstone is what makes you feel your best!

Find traditional and alternative December birthstones from our hundreds of gemstones available!



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