December boasts a remarkable array of birthstones, offering a spectrum of blue hues and unique geological origins. While historically, turquoise and zircon held prominence, modern lists include the vibrant blue topaz and the relatively recent discovery of tanzanite. This article will explore the history, gemological properties, sources, and care of these four December birthstones, providing a comprehensive overview for enthusiasts and those seeking to understand their significance.
A Quartet of Blue
For those born in December, the choice isn’t limited to a single gem. Blue topaz, blue zircon, tanzanite, and turquoise each present distinct characteristics and appeal. This selection allows individuals to choose a stone that resonates with their personal preferences and style. The diversity of these gems reflects a rich history of symbolism and appreciation, evolving over centuries to encompass both traditional and contemporary choices.
History and Lore
Historically, zircon and turquoise were the primary birthstones associated with December. Turquoise, with its long-standing cultural significance, has been prized for millennia. Zircon, while less widely known to the general public, also has a rich history as a gemstone. The inclusion of blue topaz and tanzanite as modern birthstones reflects evolving preferences and the discovery of new and captivating gems. Tanzanite, in particular, is a 20th-century addition, first identified in 1967 and gaining popularity through the marketing efforts of Tiffany & Co.
Geological Formation and Sources
The origins of these December birthstones are geographically diverse. Blue topaz is sourced from Brazil, Nigeria, Sri Lanka, and China, with Brazil being the largest producer. Turquoise is mined in the southwestern United States, particularly Arizona and Nevada, as well as Iran (where it is known as Persian turquoise) and China. Tanzanite, uniquely, is found exclusively in the Merelani Hills of northern Tanzania, near Mount Kilimanjaro. Zircon, meanwhile, is sourced from Sri Lanka, Cambodia, Myanmar, and Australia. The proximity of zircon deposits to sapphire sources is noteworthy.
Gemological Properties
Each of these gemstones possesses distinct gemological properties that contribute to its unique appearance and durability.
Blue Topaz: Blue topaz registers 8 on the Mohs scale of hardness, making it a relatively durable gemstone. It is a silicate mineral composed of aluminum and fluorine, exhibiting a glass-like luster and perfect cleavage, which contributes to its brittleness despite its hardness. The color range spans from dark inky blues (London Blue) to cooler, lighter shades (Swiss Blue and Sky Blue). The chemical formula is Al2SiO4(F,OH)4.
Blue Zircon: Blue zircon is prized for its exceptional brilliance and fire, often resembling diamonds. It ranges from 6 to 7.5 on the Mohs scale of hardness, making it fairly hard but also brittle and prone to chipping. It is commonly heat-treated to produce blue and colorless varieties, as well as orange, yellow, and red hues.
Tanzanite: Tanzanite is a richly colored pleochroic gemstone, displaying blue and violet hues that shift depending on the viewing angle. This unique multidimensional appearance sets it apart from other gemstones.
Turquoise: Information regarding the gemological properties of turquoise is limited within the provided sources.
The following table summarizes the Mohs hardness scale comparison for these gemstones:
| Gemstone | Mohs Hardness |
|---|---|
| Blue Topaz | 8 |
| Blue Zircon | 6 - 7.5 |
| Tanzanite | Data Not Available |
| Turquoise | Data Not Available |
Symbolism and Metaphysical Beliefs
While the provided sources do not delve deeply into the metaphysical beliefs surrounding these stones, they do hint at their symbolic significance. The name "topaz" itself derives from the Sanskrit word for "fire." Turquoise has a long history of cultural significance, though specific beliefs are not detailed in the provided materials. The sources emphasize the beauty and allure of each stone, suggesting a connection to personal expression and celebration.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of these December birthstones. Zircon, due to its tendency to abrade, is best avoided in rough conditions. Cleaning zircon involves using a soft brush and mild soap in warm water; ultrasonic and steam cleaners are not recommended. Blue topaz, while relatively hard, is somewhat brittle and should be handled with care. The sources provide specific care instructions for each gem, emphasizing gentle cleaning methods and avoiding harsh conditions. Exposure to heat can alter the color of some zircon, and prolonged exposure to bright light may cause some heat-treated stones to revert to their original color.
Varieties of Blue Topaz
Within the realm of blue topaz, several distinct varieties are recognized based on color intensity. London Blue topaz exhibits a deep, inky blue color, highly prized by collectors. Swiss Blue topaz displays a vibrant, medium-light blue hue, while Sky Blue topaz offers a pale, airy aqua color. The depth of color significantly impacts the value, with London Blue generally being the most sought after. Most commercially available blue topaz is produced by irradiating naturally colorless topaz.
Purchasing December Birthstone Jewelry
Blue topaz jewelry is widely available from both brick-and-mortar stores and reputable online retailers. When purchasing December birthstone jewelry, it is advisable to consult trusted retailers to ensure quality and authenticity. The sources mention James Allen, Blue Nile, CustomMade, Angara, and White Flash as potential vendors.
Tanzanite: A Modern Marvel
Tanzanite’s story is relatively recent. Discovered in 1967 and initially mistaken for sapphire, it was quickly identified as a unique variety of zoisite. Tiffany & Co. recognized its market potential and named it after its country of origin, Tanzania, to promote consumer recognition. It officially joined the December birthstone lineup in 2002.
Durability Considerations
While blue topaz is relatively durable, blue zircon is more brittle and susceptible to chipping, making protective settings crucial, especially for rings or frequently worn pieces. The sources emphasize the importance of considering durability when selecting jewelry, particularly for everyday wear.
Conclusion
December’s birthstones – blue topaz, blue zircon, tanzanite, and turquoise – offer a captivating range of colors, histories, and gemological properties. From the ancient allure of turquoise and zircon to the modern appeal of blue topaz and tanzanite, these gems provide a diverse selection for those born in the final month of the year. Understanding their unique characteristics and proper care ensures that these beautiful stones will be cherished for generations.