December is unique among months for possessing not one, but four officially recognized birthstones: Tanzanite, Zircon, Turquoise, and Blue Topaz. This multiplicity reflects a fascinating evolution in birthstone traditions, shifting from ancient associations to modern standardization. While Turquoise historically held prominence, the 20th and 21st centuries have seen the addition of Tanzanite, Zircon, and Blue Topaz, broadening the options for those born in the final month of the year. This article will explore the history of these December birthstones, their geological origins, gemological properties, and the cultural significance that has cemented their place in modern jewelry and tradition.
A History of Shifting Associations
The concept of birthstones dates back centuries, with origins in ancient civilizations. However, the standardization of which gem corresponded to which month is a relatively recent development. Early traditions varied widely, with different cultures assigning different stones based on astrological signs or personal preference. The modern birthstone list began to take shape in 1912 when the National Association of Jewelers met to create an official standardized list for American jewelers. This list consolidated various customs, prioritizing stones readily available for sale and promotion.
The initial list was later modified in 1952 by the Jewelry Industry Council of America, adding several stones, including Zircon to the December roster. Further adjustments continued into the 21st century, with Tanzanite being added to December’s selection in 2002, reflecting its growing popularity and market presence. This demonstrates that the designation of birthstones is not static, but rather a dynamic process influenced by historical precedent, commercial considerations, and evolving tastes.
The Allure of Tanzanite
Tanzanite is the newest addition to the December birthstone family, discovered relatively recently in 1967 beneath the slopes of Mount Kilimanjaro in Tanzania. Initially known as “blue-violet zoisite,” the gemstone was rebranded by Tiffany & Co. in 1968. Recognizing the marketing potential of a unique and evocative name, Tiffany’s renamed the gem Tanzanite, honoring the country of its origin. This strategic decision significantly boosted the gem’s profile and desirability.
Tanzanite is a mineral belonging to the zoisite family. Most Tanzanite begins as brownish zoisite, requiring heat treatment to reveal the vibrant blue to violet hues that characterize the gem. Fortunately, this color change is permanent, and does not affect the gem’s durability. The resulting color is highly sought after, and Tanzanite is often set in earrings or pendants due to its relative fragility. While not ideal for daily wear in a ring, protective settings can allow it to be enjoyed as a special-occasion jewel.
Cleaning Tanzanite requires gentle care. Warm, soapy water is the recommended method, while ultrasonic and steam cleaners should be avoided. Tanzanite is susceptible to cracking if exposed to very high temperatures or sudden temperature changes and can be attacked by hydrochloric and hydrofluoric acids.
Zircon: A Gem Misunderstood
Zircon boasts a history far older than Tanzanite, with roots stretching back thousands of years. Ancient civilizations often confused it with diamonds due to its brilliance, a distinction that wasn’t clearly established until the late 18th century. The name “zircon” itself has undergone several transformations, originating from the Persian “zargun” (meaning “golden”), evolving through French and German iterations before settling on the English “zircon.”
Zircon ranges in hardness from 6 to 7.5 on the Mohs scale. It is commonly heat-treated to produce the blue and colorless varieties popular in jewelry, as well as orange, yellow, and red hues. While generally stable when exposed to light, some heat-treated zircons may revert to their original color (typically light brown) after prolonged exposure to bright light. Exposure to heat can also alter the color of some zircon specimens.
Care for Zircon involves avoiding rough conditions that could cause abrasion. It is best to remove zircon jewelry during activities like gardening, sports, or dishwashing. Cleaning should be performed with a soft brush and mild soap in warm water; ultrasonic and steam cleaners are not recommended.
Turquoise: The Traditional December Stone
Traditionally, Turquoise has been considered the primary birthstone for December. It is celebrated for its distinctive blue-green color, a hue that evokes images of serene waters and clear skies. The gem is often found near sapphire sources, with notable deposits in Sri Lanka, Australia, Myanmar, Vietnam, and Cambodia.
Symbolism and Meaning
Each of December’s birthstones carries its own unique symbolism. Tanzanite is believed to represent change and spiritual growth, fostering peace, higher thinking, and intuition. It is thought to dispel negative feelings and promote a sense of calm and balance, enhancing communication and understanding. Turquoise, steeped in history, is associated with protection, healing, and good fortune. Zircon, with its ancient origins, symbolizes prosperity, wisdom, and honor.
Gemological Properties at a Glance
The following table summarizes key gemological properties of the December birthstones:
| Gemstone | Chemical Formula | Hardness (Mohs) | Color(s) | Treatment(s) |
|---|---|---|---|---|
| Tanzanite | Ca₂Al₃(SiO₄)₃(OH) | 6-7 | Blue, Violet | Heat |
| Zircon | ZrSiO₄ | 6-7.5 | Blue, Colorless, Orange, Red | Heat |
| Turquoise | CuAl₆(PO₄)₄(OH)₈·4H₂O | 5-6 | Blue-Green | Waxing, Dyeing |
Care and Cleaning Considerations
The varying hardness levels of December’s birthstones necessitate different care approaches. Tanzanite and Zircon, with their moderate hardness, require gentle handling and protection from abrasions. Turquoise, being the softest of the group, is particularly susceptible to scratches and damage. All three gems benefit from regular cleaning with mild soap and warm water, avoiding harsh chemicals and abrasive materials. Ultrasonic and steam cleaners are not recommended for Tanzanite or Zircon, and should be avoided altogether for Turquoise.
Conclusion
The story of December’s birthstones is a testament to the evolving nature of tradition and the enduring appeal of beautiful gemstones. From the ancient prominence of Turquoise to the modern additions of Tanzanite, Zircon, and Blue Topaz, each gem offers a unique blend of history, beauty, and symbolism. The diversity of options allows individuals born in December to choose a stone that resonates with their personal style and beliefs, celebrating the spirit of the season and the unique qualities of this final month of the year.