A Comprehensive Guide to December's Birthstones: Turquoise, Zircon, Tanzanite, and Blue Topaz

December is a unique month in the world of gemology, distinguished by its offering of not one, but four official birthstones. This abundance provides those born in the final month of the year a remarkable variety of choices, each with its own distinct history, color, and character. The traditional and most historically significant birthstone is Turquoise, a gem revered for millennia. It is joined by Zircon, known for its brilliant fire; Tanzanite, a relative newcomer prized for its mesmerizing violet-blue hues; and Blue Topaz, a popular modern alternative. Together, these stones represent a spectrum of blue and green shades that perfectly capture the essence of winter, symbolizing wisdom, tranquility, protection, and prosperity.

This comprehensive guide explores the rich tapestry of December's birthstones, delving into their historical significance, geological origins, unique gemological properties, and the care required to maintain their beauty. By examining each gemstone in detail, we uncover the stories that have cemented their place as cherished symbols for those born in December.

History and Lore

The history of December's birthstones is as varied as the gems themselves, stretching from ancient civilizations to modern markets. Each stone carries a legacy of cultural beliefs, royal adornment, and symbolic meaning.

Turquoise: The Ancient Protector

Turquoise stands as the oldest and most traditional birthstone for December. Its use dates back thousands of years, with evidence of its reverence in cultures across the globe. Ancient Egyptians adorned themselves with turquoise, and it was famously used in the burial mask of King Tutankhamun, signifying its importance in the afterlife. The gem was thought to offer protection from harm, including falls and negative energy. The name "turquoise" itself has European origins, derived from the French phrase pierre turquoise, meaning "stone of Turkey." This name was given because the gem was first brought to Europe from Turkish bazaars. For centuries, turquoise has been a symbol of wisdom, tranquility, and friendship, cherished by royalty and common folk alike.

Zircon: The Gem of Royalty and Misunderstanding

Blue Zircon is the other traditional December birthstone. For centuries, it was confused with the more expensive blue diamond due to its exceptional brilliance and fire. This confusion led to Zircon adorning the crowns and jewels of European royalty throughout the Middle Ages. While it has a long and storied history, its identity has often been conflated with other stones, particularly the man-made cubic zirconia, which has caused some modern confusion. However, true Zircon is a natural gemstone with a history all its own, long valued for its dazzling sparkle and protective qualities.

Tanzanite: The Modern Marvel

In stark contrast to the ancient lineage of Turquoise and Zircon, Tanzanite is a recent addition to the gem world. Discovered in the Merelani Hills of Tanzania in the late 1960s, this gemstone was introduced to the market by Tiffany & Co., which recognized its stunning beauty and launched a major marketing campaign. Its rapid rise to prominence led to its official designation as a December birthstone. The story of Tanzanite is one of modern discovery and marketing success, making it a gemstone with a history that is still being written.

Blue Topaz: The Popular Alternative

Blue Topaz has gained significant popularity in recent times and is now frequently considered a mainstream December birthstone. While not traditionally listed as a primary birthstone, its widespread appeal and availability have earned it a place as a key alternative. Its expansion onto the list of recognized December gems offers consumers more flexibility in price, durability, and style, solidifying its status as a modern choice for December birthdays.

Geological Formation and Sources

Understanding how and where these gemstones form reveals the unique geological processes that create their distinct colors and properties. The sources of these gems are concentrated in specific regions around the world, each contributing to the gem's character.

Turquoise: A Product of Arid Lands

Turquoise is a secondary mineral that forms when water containing copper and aluminum seeps through pre-existing rock. This process occurs in arid regions, where the evaporation of groundwater concentrates these minerals into solid form. The presence of copper dictates the stone's characteristic blue color, while iron can shift the hue toward green. The dark veins and patterns, known as "matrix," are remnants of the host rock in which the turquoise formed.

Significant sources for turquoise are primarily located in arid regions with copper-rich geological formations. The most important sources include: - The southwestern United States (notably Arizona and New Mexico) - Iran (historically the source of the most prized Persian turquoise) - Egypt - China - Mexico - Parts of Central Asia and Africa

Zircon: An Ancient Mineral

Zircon is one of the oldest minerals on Earth, containing trace elements that give it a wide range of colors. The blue variety, which is prized for December, is often created through a heat treatment process that transforms brownish zircon into the desired vibrant blue shade. This treatment is a standard industry practice and is stable, making the blue color permanent.

Tanzanite: Found in Only One Place

Tanzanite's geological story is remarkably unique. It is a variety of the mineral zoisite and is found in only one location on the entire planet: the Merelani Hills of Tanzania. Its formation is linked to a specific geological event that altered the chemistry of the host rock, allowing for the creation of this extraordinary gem. This extreme rarity is a major factor in its value and allure.

Blue Topaz: Common Stone, Captivating Color

Topaz itself is a silicate mineral that forms in igneous rocks, particularly in cavities within granites and rhyolites. The pure form of topaz is typically colorless, but trace impurities can produce a range of colors. The vibrant blue of the December birthstone is most often the result of irradiation and heat treatment applied to colorless topaz. Major sources for topaz include Brazil, Sri Lanka, and Nigeria.

Gemological Properties

Each of December's birthstones possesses a unique set of physical and chemical characteristics that define its identity, durability, and appearance. These properties are critical for gemologists in identifying stones and for consumers in understanding how to care for their jewelry.

Gemstone	Mineral Family	Chemical Formula	Hardness (Mohs Scale)	Key Characteristics
Turquoise	Phosphate	CuAl₆(PO₄)₄(OH)₈·4H₂O	5 - 6	Opaque, often contains a dark matrix; color ranges from sky blue to green.
Zircon	Silicate	ZrSiO₄	6.5 - 7.5	High refractive index gives it exceptional brilliance and fire; often heat-treated to achieve blue color.
Tanzanite	Sorosilicate	Ca₂Al₃(SiO₄)₃(OH)	6.5 - 7	Trichroic, showing blue, violet, and burgundy hues; pleochroic, showing different colors from different angles.
Blue Topaz	Silicate	Al₂SiO₄(F,OH)₂	8	Durable and hard; its blue color is typically achieved through treatment of colorless topaz.

Turquoise: The Soft and Opaque Gem

As noted in the provided materials, Turquoise ranks between 5 and 6 on the Mohs Hardness Scale. This relatively low hardness makes it susceptible to scratches and requires careful handling. It is typically opaque, meaning light does not pass through it. Its color is derived from copper (blue) and iron (green), and many specimens feature a distinctive matrix—the web-like pattern of the host rock.

Zircon: The Brilliant Sparkler

Zircon has a hardness of 6.5 to 7.5 on the Mohs scale, making it relatively durable and suitable for jewelry, though care should be taken to avoid hard impacts that could cause chipping. Its most notable gemological property is its high refractive index, which is higher than that of a diamond, giving it exceptional brilliance and fire. The blue color seen in December birthstones is typically the result of heat treatment applied to brown zircon.

Tanzanite: The Trichroic Treasure

With a hardness of 6.5 to 7, Tanzanite is somewhat softer than Zircon or Topaz but is still suitable for jewelry with proper care. Its most fascinating property is its trichroism—the ability to display three different colors (blue, violet, and burgundy) when viewed from different crystallographic directions. This characteristic gives the stone a complex and dynamic appearance. The vibrant blue-violet color for which it is famous is its most sought-after hue.

Blue Topaz: The Durable Blue

Blue Topaz is the hardest of the four December stones, with a rating of 8 on the Mohs scale. This makes it highly resistant to scratching and an excellent choice for jewelry that is worn daily. As mentioned, its natural color is rare, and the commercially available blue varieties are almost always the result of treating colorless topaz with irradiation and heat. This process produces consistent and attractive shades of blue, from sky blue to the deeper Swiss Blue and London Blue tones.

Symbolism and Metaphysical Beliefs

Beyond their physical beauty, December's birthstones are rich in symbolism and are believed by many to possess metaphysical properties. These beliefs add a layer of personal meaning to the gems, making them more than just decorative objects.

Turquoise is widely regarded as a stone of protection, wisdom, and tranquility. It is believed to guard against negative energy, promote inner calm, and foster clear communication. Historically, it was a talisman for travelers and warriors, and today it is a symbol of friendship and positive fortune.
Zircon is associated with honor, purity, and wisdom. It is believed to help its wearer achieve their goals, promote spiritual growth, and ward off nightmares. Its brilliant light is thought to illuminate the path of its owner.
Tanzanite, as a modern discovery, has quickly developed its own lore. It is often called the "stone of transformation" and is believed to facilitate a higher consciousness, intuition, and perception. It symbolizes uniqueness and clarity of purpose, fitting for a gem found in only one place on Earth.
Blue Topaz is linked to calm, clarity, and love. It is believed to soothe the mind, reduce stress, and promote clear and honest communication. Its cool blue color is associated with peace and tranquility.

Care and Cleaning

Proper care is essential to preserve the beauty and longevity of any gemstone. The varying hardness and characteristics of December's birthstones necessitate different approaches to maintenance.

Caring for Turquoise

Due to its relatively low hardness (5-6 on the Mohs scale) and porous nature, turquoise requires the most care. It can be easily scratched by harder materials and is susceptible to damage from chemicals, including cosmetics, lotions, and even the natural oils in skin. To clean turquoise, simply use a soft, dry cloth. Avoid soaking it in water or using ultrasonic cleaners, as this can damage the stone and any surrounding materials.

Caring for Zircon and Tanzanite

Both Zircon and Tanzanite have a moderate hardness (around 6.5 to 7) and can be prone to chipping if struck against a hard surface. It is best to store them separately from other jewelry to prevent scratching. Cleaning can be done with warm water, a mild soap, and a soft brush. They are generally safe from standard chemical exposures but, like all fine jewelry, should be removed before engaging in strenuous activities.

Caring for Blue Topaz

As the hardest of the group (8 on the Mohs scale), Blue Topaz is quite durable and resistant to scratching. However, it can be brittle and may cleave if struck with sufficient force. It is also sensitive to heat and sudden temperature changes. Standard cleaning with warm soapy water and a soft brush is safe. Ultrasonic and steam cleaners are generally acceptable, but caution is advised if the stone has been fracture-filled, which is rare for topaz but possible.

Conclusion

The birthstones of December—Turquoise, Zircon, Tanzanite, and Blue Topaz—offer a remarkable diversity of history, geology, and aesthetic appeal. From the ancient, protective power of Turquoise to the brilliant fire of Zircon, the singular beauty of Tanzanite, and the durable elegance of Blue Topaz, each gem provides a unique connection to the natural world and human history. This selection allows individuals born in December to choose a stone that not only reflects their personal style but also resonates with their individual journey. Whether selected for its traditional significance, its symbolic meaning, or simply its captivating color, a December birthstone is a timeless treasure, embodying the wisdom, peace, and clarity of the winter month.