For individuals born on the second day of December, the selection of birthstones is notably diverse, reflecting a rich tapestry of geological origins, historical narratives, and cultural symbolism. While no single gemstone is exclusively designated for December 2nd, the month itself is traditionally associated with a distinctive quartet of gems: Turquoise, Zircon, Tanzanite, and Blue Topaz. Each possesses a unique character, from ancient protective talismans to modern marvels of color. This article provides a comprehensive exploration of these four gemstones, detailing their gemological properties, historical significance, symbolic meanings, and practical care, offering a detailed guide for gemstone enthusiasts, jewelry buyers, and students of gemology.
Historical Origins and the Path to Birthstone Status
The tradition of assigning specific gemstones to calendar months has deep roots, with some scholars tracing it back to the biblical descriptions of Aaron’s breastplate or the foundations of the New Jerusalem. The modern, standardized list of birthstones, however, was established in 1912 by the American National Association of Jewelers (now the Jewelers of America). This list originally designated Turquoise and Zircon as the two official birthstones for December. Over time, consumer preference and market trends have led to an expansion of this list. The Gemological Institute of America (GIA) now recognizes Turquoise, Tanzanite, and Zircon as December’s primary birthstones, while Blue Topaz has gained significant popularity and is frequently included as a mainstream option.
Turquoise holds the distinction of being the most historically recognized December birthstone. Its use dates back millennia, with archaeological evidence pointing to its reverence in ancient Egypt. The oldest known turquoise mines, dating to approximately 3200 BCE, were located in this region. The gem’s name itself is a testament to its journey through trade routes; it was mined in Persia and the Sinai Peninsula, transported to Europe via the gem markets of Constantinople (modern-day Istanbul, Turkey), and subsequently became known as "turkis" or "turkeystone."
Zircon shares an equally ancient pedigree. References to this gem appear in Hebrew, Arabic, and Greek texts as early as the 5th century BCE. The word "zircon" is derived from the Persian term "zargun," which translates to "gold-colored," a nod to the warm hues found in some of its varieties. Historically, its brilliant fire and wide range of colors led to its use in imitations for other gems, with its colorless forms being particularly prized.
The introduction of Tanzanite is a more recent development. This gemstone was not known to the world until the 1960s, when it was discovered in a single, small area in the Merelani Hills of Tanzania. Its rapid rise to prominence and acceptance as a birthstone highlights the dynamic nature of gemology and market trends.
Blue Topaz, while not originally on the 1912 list, has become a staple in modern jewelry. Its widespread availability and attractive blue hues have cemented its place as a popular alternative for December birthdays, offering a more affordable option compared to some of its counterparts.
Geological Formation and Global Mining Sources
The formation and sourcing of these gemstones are as varied as their histories, each requiring specific geological conditions.
Turquoise is a secondary mineral that forms in arid regions through a process involving the percolation of water rich in copper and aluminum through pre-existing rock. This process typically occurs in areas with copper-rich geological formations and specific climatic conditions that facilitate the precipitation of the mineral. The most significant global sources include the southwestern United States (notably Arizona, New Mexico, and Nevada), Iran, Egypt, China, Mexico, and parts of Central Asia and Africa. Turquoise is often characterized by its distinctive matrix—the host rock that becomes part of the gem, creating intricate, spiderweb-like patterns that add to its unique appearance.
Zircon is a zirconium silicate mineral that forms primarily in pegmatites and metamorphic rocks. It is a common accessory mineral found in many igneous and metamorphic rocks, but gem-quality crystals are rarer. Zircon is mined in several countries, including Cambodia, Sri Lanka, Thailand, Australia, and the United States. The gem is renowned for its high refractive index and strong dispersion, which give it exceptional brilliance and fire.
Tanzanite is a variety of the mineral zoisite. Its formation is geologically unique; it is believed to have been created by a specific combination of geological events, including intense heat and pressure, that transformed the original zoisite crystals. The primary, and for a long time the only, source of gem-quality tanzanite is the Merelani Hills in the Lelatema Mountains of Tanzania. The gem is often found in close proximity to another December birthstone, zircon, and is typically subjected to heat treatment to enhance its blue-to-violet color.
Blue Topaz is a silicate mineral of the aluminum and fluorine group. Natural blue topaz is extremely rare; the vast majority of blue topaz on the market today is created by irradiating colorless topaz, which is abundant and relatively inexpensive. Major sources of the colorless topaz include Brazil, Nigeria, and Sri Lanka. The irradiation process is safe and permanent, resulting in the appealing shades of sky blue, Swiss blue, and London blue that are popular in jewelry.
Gemological Properties: A Scientific Profile
Understanding the physical and optical properties of these gemstones is crucial for identification, valuation, and care. The following table summarizes key gemological data for each stone.
| Gemstone | Mineral Group | Chemical Formula | Hardness (Mohs Scale) | Refractive Index | Key Characteristics |
|---|---|---|---|---|---|
| Turquoise | Phosphate | CuAl₆(PO₄)₄(OH)₈·4H₂O | 5 - 6 | 1.61 - 1.65 | Often porous, can be dyed or stabilized. Color ranges from blue to green. |
| Zircon | Silicate | ZrSiO₄ | 6.5 - 7.5 | 1.92 - 2.01 | High refractive index, strong dispersion ("fire"). Heat treatment can improve color. |
| Tanzanite | Silicate (Zoisite) | Ca₂Al₃(SiO₄)₃(OH) | 6.5 - 7 | 1.69 - 1.70 | Pleochroic (shows different colors from different angles). Almost always heat-treated. |
| Blue Topaz | Silicate | Al₂SiO₄(F,OH)₂ | 8 | 1.63 - 1.64 | Naturally rare; most commercial blue topaz is irradiated colorless topaz. |
Turquoise is relatively soft, with a hardness of 5 to 6 on the Mohs scale. This makes it susceptible to scratching and requires careful handling. Its porosity means it can absorb oils and chemicals, which may alter its color over time. High-quality turquoise is prized for its uniform color and minimal matrix, though some collectors value the intricate patterns of the matrix.
Zircon is significantly harder, with a hardness ranging from 6.5 to 7.5. This makes it durable enough for most types of jewelry, though it can be brittle due to its crystal structure. Its most remarkable optical properties are its high refractive index and strong dispersion, which give it a brilliance and fire that can rival diamond. Zircon is also pleochroic, meaning it can display different colors when viewed from different crystal directions. It is commonly heat-treated to produce colorless or blue varieties, a stable and widely accepted practice.
Tanzanite has a hardness of 6.5 to 7. Its most defining feature is its strong pleochroism, typically displaying blue, violet, and burgundy tones depending on the viewing angle. This property is so pronounced that cutters must orient the rough stone carefully to present the desired blue-violet color in the final gem. Virtually all tanzanite on the market has been heat-treated to achieve its vivid blue hue, a process that mimics the natural geological conditions that would have produced the gem over millions of years.
Blue Topaz is one of the hardest and most durable gemstones, with a Mohs hardness of 8. This makes it an excellent choice for rings and other jewelry that may encounter daily wear. Its transparency and vitreous luster make it a popular gem for faceted cuts. The color of commercial blue topaz is entirely a result of post-mining irradiation treatment, which is considered stable and safe.
Symbolism and Metaphysical Beliefs
Across cultures and centuries, these gemstones have been imbued with profound symbolic meanings and metaphysical attributes.
Turquoise is perhaps the most culturally significant in this regard. It has long been regarded as a protective talisman. Ancient Egyptians believed it could ward off evil and protect the wearer from harm. In Tibetan culture, turquoise is considered a gem of fortune, health, and success, and was even used as a form of currency. Native American tribes of the Southwest associate the stone with youth, strength, and a connection to the earth. It is also believed to promote healing, bring good fortune, and preserve friendship when given as a gift. Some lore suggests that turquoise can warn its wearer of impending illness or danger by changing color.
Zircon, particularly its colorless variety, has been historically associated with wisdom, prosperity, and honor. It was believed to promote sound sleep and ward off nightmares. The gem’s fiery brilliance led to its association with spiritual light and clarity of thought. In some traditions, zircon is thought to help its wearer achieve their goals and attract abundance.
Tanzanite, as a modern discovery, does not have centuries of traditional lore. However, its symbolism has been shaped by its unique properties and origin. It is often associated with transformation, spiritual awakening, and intuition. Its striking trichroic color display is seen as a metaphor for the multifaceted nature of the self. Some crystal healing practices attribute tanzanite with properties that promote calm, balance, and communication.
Blue Topaz is commonly linked to tranquility, clarity, and emotional balance. Its cool blue hues are said to soothe the mind and reduce stress. It is often called the "stone of love and good fortune" and is believed to enhance communication and self-expression. In metaphysical circles, it is associated with the throat chakra, promoting honest and clear communication.
Care and Maintenance
Proper care is essential to preserve the beauty and longevity of these gemstones, and the recommended practices vary significantly based on their physical properties.
Turquoise requires the most diligent care due to its relative softness and porosity. It should be protected from scratches, chemicals, perfumes, and extreme temperatures. Cleaning should be done with a soft, dry cloth; avoid ultrasonic cleaners, steam cleaners, and harsh soaps. To maintain its color, it is advisable to store turquoise jewelry separately from other pieces.
Zircon is durable but can be brittle. It is best to avoid rough handling and protect it from sharp blows. While it can be cleaned with warm soapy water and a soft brush, ultrasonic cleaners should be used with caution, as vibrations may cause fractures in stones with inclusions. Sudden temperature changes should also be avoided.
Tanzanite has good hardness but can be susceptible to chipping due to its crystal structure. It is best suited for pendants and earrings rather than rings that are subject to hard knocks. Cleaning can be done with warm soapy water and a soft brush. As with zircon, ultrasonic cleaners are not recommended, and steam cleaning should be avoided.
Blue Topaz is the most durable of the four, making it relatively easy to care for. It can be safely cleaned in an ultrasonic cleaner and with warm soapy water. However, as with all gemstones, it is wise to avoid sudden temperature changes and harsh chemicals. Its durability makes it an excellent choice for everyday jewelry.
Conclusion
The birthstones for December—and by extension, for those born on December 2nd—offer a remarkable spectrum of color, history, and meaning. From the ancient, protective Turquoise to the brilliantly fiery Zircon, the newly discovered and mystical Tanzanite, and the durable, tranquil Blue Topaz, each gemstone provides a unique connection to the natural world and human culture. Their varied origins, from arid copper-rich landscapes to single mountain valleys in Tanzania, reflect the diverse processes that create beauty beneath the Earth's surface. For the gemstone enthusiast, the jewelry buyer, or the student of gemology, understanding these stones enriches the experience of owning and wearing them. Whether chosen for their symbolic significance, their aesthetic appeal, or their historical legacy, these gemstones are enduring treasures that celebrate the individuality of every December birthday.