December is unique among the months, boasting not one, but five recognized birthstones: zircon, topaz, tanzanite, lapis lazuli, and turquoise. This abundance offers a diverse selection of colors, histories, and price points, catering to individual preferences and providing a rich tapestry of options for those born in the final month of the year. While turquoise and zircon have historically been considered the primary December birthstones, modern lists include blue topaz and tanzanite, expanding the choices available. These gemstones, ranging from the oldest known to a recent discovery, each possess distinct characteristics and cultural significance.
History and Lore
The tradition of associating specific gemstones with birth months dates back to ancient times, though the specific stones assigned have evolved over centuries. The practice originated with the breastplate of Aaron, described in the Book of Exodus, which contained twelve gemstones representing the tribes of Israel. Over time, these associations were adapted and refined, eventually leading to the modern birthstone lists.
Turquoise, one of the oldest known birthstones, has a history stretching back millennia. Zircon, too, boasts ancient origins, being among the earliest minerals formed on Earth. Topaz’s name is believed to derive from the Sanskrit word “tapas,” meaning fire, reflecting its historical association with strength and protection. Tanzanite, in contrast, is a relatively recent discovery, first identified in Tanzania in the 1960s, making it the newest addition to the December birthstone family.
The use of these gemstones in jewelry and adornment also has a long history. They have been used in engagement rings, wedding bands, and necklaces, not merely for their aesthetic appeal but also for the metaphysical properties attributed to them. This tradition isn’t a recent fashion trend, but one rooted in medieval times and earlier.
Geological Formation and Sources
The formation of these December birthstones occurs through diverse geological processes. Turquoise is a secondary mineral, forming in arid regions through the interaction of copper-rich solutions with aluminum and phosphorus-bearing rocks. It is often found in association with copper deposits. Historically, turquoise has been mined in Persia (modern-day Iran), and remains a significant source, but it is also found in the United States, particularly in Arizona and New Mexico.
Zircon forms in igneous rocks and metamorphic rocks, crystallizing from magma or during the alteration of existing rocks. It is found in a variety of locations worldwide, including Sri Lanka, Cambodia, and Australia. Blue zircon, a popular December birthstone, often undergoes heat treatment to enhance its color.
Topaz is formed in igneous rocks and pegmatites, often in association with fluorine-rich fluids. Major sources of topaz include Brazil, Nigeria, and Russia. While naturally occurring blue topaz is rare, most blue stones available on the market are created by irradiating colorless topaz and then heating it.
Tanzanite, uniquely, is found in only one location: a small area near Mount Kilimanjaro in Tanzania. This limited source contributes to its rarity and value. It forms in metamorphic rocks, created by intense heat and pressure.
Gemological Properties
Each December birthstone possesses distinct gemological properties that contribute to its unique appearance and characteristics.
Turquoise: This opaque gemstone is recognized by its distinctive robin’s egg blue to greenish-blue color, often featuring unique veining patterns. It is relatively soft, with a Mohs hardness of 5-6, making it susceptible to scratching.
Zircon: Zircon is valued for its brilliant fire and rainbow of colors. It has a Mohs hardness of 6.5-7.5, making it more durable than turquoise. It is often mistaken for diamond due to its high refractive index and dispersion.
Blue Topaz: Blue topaz is known for its clear, sky-blue to deep London Blue shades. It has a Mohs hardness of 8, making it a relatively durable gemstone. Topaz has a chemical formula of Al₂SiO₄(OH,F)₂.
Tanzanite: Tanzanite is prized for its unique blue to violet color. It exhibits strong pleochroism, meaning it displays different colors when viewed from different angles. It has a Mohs hardness of 6-7.
The following table summarizes key gemological properties:
| Gemstone | Chemical Formula | Hardness (Mohs) | Color(s) | Transparency |
|---|---|---|---|---|
| Turquoise | CuAl₆(PO₄)₄(OH)₈·4H₂O | 5-6 | Blue to greenish-blue | Opaque |
| Zircon | ZrSiO₄ | 6.5-7.5 | Colorless, blue, brown, etc. | Transparent |
| Blue Topaz | Al₂SiO₄(OH,F)₂ | 8 | Blue | Transparent |
| Tanzanite | Ca₂Al₃(SiO₄)₃(OH) | 6-7 | Blue to violet | Transparent |
Symbolism and Metaphysical Beliefs
Throughout history, these December birthstones have been attributed with various symbolic meanings and metaphysical properties. Turquoise is believed to dispel negative energy and provide protection against environmental pollutants. It is also thought to enhance intuition and release inhibitions.
Blue topaz is associated with calmness, love, and clarity. It is believed to channel inner wisdom and open pathways to successful opportunities.
Zircon is celebrated for its brilliance and is linked to prosperity and wisdom.
Tanzanite, due to its rarity and unique color, is often associated with transformation and spiritual growth.
Care and Cleaning
Proper care is essential to maintain the beauty and vibrancy of December birthstones. Turquoise is porous and can absorb chemicals from lotions, creams, and perfumes, potentially altering its color. It should be stored in a jewelry pouch or box to prevent scratching and exposure to these substances.
Zircon and topaz, being more durable, can be cleaned with warm soapy water and a soft brush. Avoid ultrasonic cleaners, as they may damage the stones. Tanzanite should also be cleaned gently with warm soapy water and a soft brush. Avoid harsh chemicals and abrasive cleaners for all gemstones.
Conclusion
December’s birthstones—zircon, topaz, tanzanite, lapis lazuli, and turquoise—offer a rich mix of history and symbolism, making each a unique choice for those born in this month. These stones are more than just beautiful; they reflect the wearer's personality and connect them to historical and cultural narratives. When choosing between these gemstones, careful research and consultation with experts are recommended to ensure quality and authenticity. Their unique traits demand thoughtful handling and care to maintain their beauty over time.