December boasts a unique distinction among the calendar months: it is associated with not one, but several birthstones. Historically, ruby held prominence as the December birthstone, while modern lists include turquoise, tanzanite, and zircon. This article will explore the history, lore, and gemological properties of these stones, tracing their journey from ancient beliefs to contemporary jewelry.
History and Lore
The association of gemstones with specific months dates back to biblical times, with early birthstone lists often differing from modern interpretations. Ruby was initially linked to December, a connection rooted in the gem’s vibrant red hue and symbolic associations with passion, protection, and prosperity. Ancient cultures, including those of Egypt and China, valued turquoise for millennia, believing it offered health, good fortune, and protection against harm. Turquoise was considered a talisman, safeguarding wearers from falls and disaster, and promising wealth.
The evolution of December’s birthstone selection is documented through various publications. Tiffany & Co.’s 1870 “Gregorian Birthstone Poems” pamphlet designated turquoise as the stone for December. The National Association of Jewellers (now Jewellers of America) initially listed turquoise as the primary stone in 1912, with lapis lazuli as an alternative. Zircon was added to the list in 1952 by the Jewelry Industry Council of America, and tanzanite was officially recognized as a December birthstone in 2002. This progression reflects changing preferences and the introduction of newly discovered gemstones into the market.
Lapis lazuli, once considered a December birthstone prior to the 1950s, was historically associated with royalty and artistry. It was believed to promote self-mastery and offer protection, clearing the mind and providing peace. Blue zircon, a popular variety, gained recognition as a December birthstone after 1952, symbolizing joy and emotional balance.
Geological Formation and Sources
The origins of these December birthstones vary significantly. Turquoise forms in relatively shallow deposits, often near copper mines, through a chemical reaction involving water, copper ions, and aluminum phosphates. It is found in arid regions worldwide, with notable sources including the southwestern United States, particularly New Mexico, where it has been mined for centuries and is the official state gem.
Tanzanite, a relatively recent discovery, is found exclusively in the Merelani Hills of northern Tanzania. Its formation requires specific geological conditions involving intense heat and pressure, and its limited geographic origin contributes to its rarity. Zircon, a zirconium silicate, forms in igneous rocks and metamorphic rocks, and is found in various locations globally, including Sri Lanka, Cambodia, and Australia. Ruby, a variety of the mineral corundum, forms in metamorphic rocks and is sourced from locations such as Myanmar (Burma), Thailand, and Sri Lanka.
Gemological Properties
Each December birthstone possesses unique gemological characteristics. Turquoise is a semi-translucent to opaque gem, ranging in color from blue to green, often exhibiting matrix patterns. Its hardness on the Mohs scale is relatively low, ranging from 5 to 6, requiring careful handling.
Tanzanite, a trichroic gemstone, displays blue, violet, and burgundy hues depending on the viewing angle. It has a hardness of 6.5 to 7 on the Mohs scale. Zircon exhibits a wide range of colors, including blue, brown, red, and yellow. Blue zircon is the most commonly associated with December. Its hardness ranges from 6.5 to 7.5 on the Mohs scale. Ruby, renowned for its intense red color, boasts a hardness of 9 on the Mohs scale, making it exceptionally durable.
A comparative table of key properties is provided below:
| Gemstone | Chemical Formula | Hardness (Mohs) | Color(s) | Transparency |
|---|---|---|---|---|
| Turquoise | CuAl6(PO4)4(OH)8·4H2O | 5-6 | Blue, Green | Opaque |
| Tanzanite | Ca2Al3(SiO4)3(OH) | 6.5-7 | Blue, Violet, Burgundy | Transparent |
| Zircon | ZrSiO4 | 6.5-7.5 | Blue, Brown, Red, Yellow | Transparent |
| Ruby | Al2O3 | 9 | Red | Transparent |
Symbolism and Metaphysical Beliefs
Throughout history, these gemstones have been imbued with symbolic meanings and metaphysical properties. Ruby has long been associated with passion, courage, and vitality, believed to sharpen the mind and encourage courtly love. Turquoise is considered a protective stone, promoting good fortune, health, and prosperity. It was thought to safeguard against accidents and bring wealth.
Lapis lazuli, historically valued by royalty and artists, symbolizes self-mastery, protection, and mental clarity. Blue zircon is believed to foster joy and emotional balance. Tanzanite is considered a soothing and protective stone, facilitating the sharing of spiritual insights. Blue topaz, another December birthstone, is thought to stimulate self-esteem and enhance learning abilities, aligning meridians and calming emotions.
Care and Cleaning
The care and cleaning of these December birthstones vary based on their hardness and composition. Turquoise, being relatively soft, requires gentle handling and should be protected from scratches and harsh chemicals. Cleaning can be done with a soft cloth and mild soapy water. Tanzanite and zircon, with moderate hardness, can be cleaned with warm soapy water and a soft brush. Ruby, being exceptionally durable, can withstand more rigorous cleaning methods, but ultrasonic cleaners should be used with caution. All gemstones benefit from regular cleaning to maintain their brilliance. It is recommended to bathe crystals in full moonlight regularly to energize them and cleanse them by placing them on selenite or moving them through sage smoke. Removing jewelry daily to allow it to rest is also advised.
Conclusion
December’s birthstones – ruby, turquoise, tanzanite, and zircon – represent a diverse range of colors, histories, and symbolic meanings. From ruby’s ancient association with passion and protection to tanzanite’s modern appeal and unique trichroism, each gem offers a distinct connection to the month of December. The evolving list of December birthstones reflects changing cultural preferences and the discovery of new and captivating gemstones, providing individuals with a variety of options to celebrate their December birthdays. These gems continue to be cherished for their beauty, lore, and enduring significance.