December is unique among the calendar months, boasting not one, but four recognized birthstones: turquoise, tanzanite, blue topaz, and blue zircon. Each of these gemstones presents a distinct shade of blue, mirroring the cool tones of the winter season, and carries its own rich history and symbolism. While turquoise holds the distinction as the most traditional December birthstone, the others – particularly tanzanite – have gained prominence in recent decades, offering a diverse range of options for those born in the twelfth month.
History and Lore
The history of December birthstones is a story of evolving traditions. Turquoise has been cherished for centuries, with ancient cultures recognizing its spiritual and healing qualities. The other three stones represent more recent additions to the December birthstone family. Tanzanite was only discovered in Tanzania in 1967 and quickly popularized by Tiffany & Co., while blue zircon and blue topaz have seen increased recognition as modern alternatives.
In India, turquoise is specifically associated with the zodiac sign Sagittarius (November 21 to December 21) and is believed to possess healing powers and promote good health. Traditional Hindu practices often involve wearing birthstone rings set to ensure direct skin contact with the gem. This practice highlights the long-held belief in the power of gemstones to influence well-being.
Geological Formation and Sources
The origins of these December birthstones are geographically diverse. Turquoise, a copper aluminum phosphate, forms in semi-humid and dry environments where rock is present. It is created when chemicals seep from adjacent rocks through rain and groundwater. The blue hue of turquoise is derived from copper, while iron contributes to green variations.
Blue zircon is mined primarily in Thailand, Cambodia, and Vietnam. It is a natural gem, distinct from synthetic cubic zirconia, and is found in a variety of colors, with heat treatment often used to achieve the desired pastel blue shade. Zircon is notable for containing trace amounts of uranium and thorium, making it valuable in radiometric dating, with some specimens estimated to be over 4.4 billion years old.
Tanzanite, a relatively recent discovery, is found exclusively in a small geographical area around Mount Kilimanjaro in Tanzania. Its unique geological setting contributes to its rarity and value. Blue topaz, while often naturally occurring, is frequently produced by irradiating naturally colorless topaz.
Gemological Properties
Each of the December birthstones possesses unique gemological properties. Turquoise is an opaque stone, ranging in color from brilliant blue to green, often exhibiting veined patterns due to the remnants of the host rock. These veins can be black, silver, tan, or gold.
Blue zircon boasts a high refractive index, contributing to its brilliance. It has been used as a diamond substitute for centuries due to its sparkling appearance.
Blue topaz is a silicate mineral composed of aluminum and fluorine, with a glass-like luster and deep cleavage, making it somewhat delicate despite its hardness. Blue topaz varieties are categorized by color intensity: London Blue (deep inky blue), Swiss Blue (vibrant medium light blue), and Sky Blue (light aqua).
Tanzanite is a transparent blue crystal, typically faceted into various shapes, displaying colors ranging from blue to purple. Its strong pleochroism means it exhibits different colors when viewed from different angles and under different lighting conditions. Heat treatment is commonly used to enhance its coloration.
The following table summarizes key properties:
| Gemstone | Chemical Formula | Color(s) | Hardness (Mohs) | Luster | Transparency |
|---|---|---|---|---|---|
| Turquoise | CuAl6(PO4)4(OH)8 | Blue to Green | 5-6 | Waxy to Vitreous | Opaque |
| Blue Zircon | ZrSiO4 | Blue | 6.5-7.5 | Adamantine | Transparent |
| Blue Topaz | Al2SiO4(F,OH)4 | Shades of Blue | 8 | Vitreous | Transparent |
| Tanzanite | Ca2Al3(SiO4)3(OH) | Blue to Purple | 6-7 | Vitreous | Transparent |
Symbolism and Metaphysical Beliefs
Throughout history, these gemstones have been attributed with various symbolic meanings and metaphysical properties. Turquoise has long been associated with protection, wisdom, and good fortune. In some cultures, it is believed to have healing powers.
Blue zircon is thought to promote wisdom, honor, and prosperity. Its association with ancient traditions suggests a connection to spiritual enlightenment.
Blue topaz is often linked to calming energy and clear communication. It is believed to enhance creativity and inspire a sense of peace.
Tanzanite, as a relatively new gemstone, is associated with transformation, intuition, and spiritual awareness. Its vibrant color is thought to stimulate the mind and encourage self-expression.
Care and Cleaning
Proper care is essential to maintain the beauty of December birthstones. Turquoise, being relatively soft, is susceptible to scratches and should be protected from harsh impacts. It is best cleaned with a soft cloth and mild soap and water. Avoid ultrasonic cleaners and harsh chemicals.
Blue zircon and blue topaz, being harder, are more durable but can still be chipped or scratched. They can be cleaned with warm soapy water and a soft brush. Avoid ultrasonic cleaners for zircon, as it may be brittle.
Tanzanite, while durable, is sensitive to heat and sudden temperature changes. It should be cleaned with warm soapy water and a soft cloth. Avoid prolonged exposure to sunlight, as it may cause fading.
Conclusion
The December birthstones – turquoise, tanzanite, blue topaz, and blue zircon – offer a captivating spectrum of blue hues and a rich tapestry of history, symbolism, and geological origins. From the ancient traditions surrounding turquoise to the modern allure of tanzanite, each gemstone provides a unique and meaningful option for those born in December. Whether chosen for their aesthetic beauty, perceived metaphysical properties, or personal significance, these gemstones continue to enchant and inspire.