December Birthstones: Turquoise, Tanzanite, and Zircon
December is unique among the months because it is associated with three official birthstones rather than just one. These gemstones—Turquoise, Tanzanite, and Zircon—offer a wide range of colors, histories, and meanings, yet all are traditionally linked by cool blue tones that reflect winter skies and icy landscapes.
This guide explores each December birthstone in detail, including its history, origin, physical properties, symbolism, and care requirements.
Why December Has Three Birthstones
The modern birthstone list was standardized in 1912 by the National Association of Jewelers (now Jewelers of America). Over time, additional stones were added to some months to provide more affordable or stylistically diverse options.
December originally featured Turquoise, with Zircon later added as an alternative. Tanzanite became an official December birthstone in 2002, making it one of the most recent additions to the modern birthstone list.
Turquoise: December’s Traditional Birthstone
Overview
Turquoise is one of the oldest known gemstones, prized for thousands of years for its distinctive blue to blue-green color. It is an opaque gemstone formed by the interaction of copper-rich water with aluminum and phosphorus minerals.
Color and Appearance
- Sky blue to greenish-blue
- Often features dark veining called a matrix
- Color depends largely on copper (blue) and iron (green) content
Historical Significance
Turquoise has been valued by many ancient civilizations:
- Ancient Egyptians used it in jewelry and burial artifacts as early as 3000 BCE
- Persians believed turquoise protected the wearer from harm
- Native American cultures, especially in the American Southwest, used turquoise in ceremonial and spiritual jewelry
Physical Properties
- Mohs hardness: 5–6
- Luster: Waxy to dull
- Transparency: Opaque
Because of its relative softness, turquoise is often stabilized to improve durability.
Symbolism and Meaning
Traditionally, turquoise is associated with:
- Protection and good fortune
- Friendship and loyalty
- Calmness and emotional balance
Tanzanite: A Rare and Modern December Birthstone
Overview
Tanzanite is a variety of the mineral zoisite and is found in only one place on Earth—near Mount Kilimanjaro in Tanzania. Discovered in 1967, it quickly gained popularity due to its vivid color and rarity.
Color and Optical Effects
- Blue to violet, sometimes with purple tones
- Exhibits pleochroism, meaning it can show different colors from different angles
- Most tanzanite is heat-treated to enhance its blue-violet hue (a stable and accepted practice)
Physical Properties
- Mohs hardness: 6–6.5
- Luster: Vitreous
- Transparency: Transparent to translucent
Tanzanite is softer than sapphire, so it’s best suited for earrings, pendants, or occasional-wear rings.
Rarity and Value
Tanzanite is considered far rarer than diamonds. Because its supply is limited to a single geographic region, it is sometimes described as a “generation gemstone,” with known deposits expected to be depleted in the future.
Symbolism and Meaning
Tanzanite is often associated with:
- Transformation and new beginnings
- Insight and intuition
- Creativity and personal growth
Zircon: The Oldest Gemstone on Earth
Overview
Zircon is frequently confused with cubic zirconia, but they are entirely different materials. Zircon is a natural gemstone, while cubic zirconia is a lab-created diamond simulant.
Some zircon crystals are estimated to be over 4 billion years old, making zircon the oldest known mineral on Earth.
Color Range
While December’s birthstone zircon is traditionally blue, zircon occurs in many colors:
- Blue (most popular for December)
- White (colorless)
- Yellow, brown, green, and red
Blue zircon is typically heat-treated to achieve its bright, sky-blue color.
Physical Properties
- Mohs hardness: 6–7.5
- Luster: Brilliant and fiery
- Transparency: Transparent to translucent
Zircon has a high refractive index, giving it exceptional sparkle—sometimes rivaling diamonds.
Symbolism and Meaning
Historically, zircon has been linked to:
- Wisdom and prosperity
- Protection during travel
- Confidence and clarity
Caring for December Birthstone Jewelry
Because December birthstones vary in hardness, care recommendations differ:
- Turquoise: Avoid water, chemicals, and prolonged sunlight
- Tanzanite: Clean gently with warm water and mild soap; avoid ultrasonic cleaners
- Zircon: Durable but brittle—store separately to prevent chipping
All three gemstones should be removed before sports, cleaning, or heavy physical activity.
Choosing the Right December Birthstone
December’s trio of birthstones offers something for every style:
- Choose turquoise for a classic, earthy, and historic look
- Choose tanzanite for rarity and rich, modern color
- Choose zircon for brilliance and exceptional sparkle
Each stone carries its own beauty, story, and significance, making December one of the most versatile birthstone months of the year.