December boasts a unique distinction among the months: it is represented by not one, but three recognized birthstones – turquoise, tanzanite, and zircon. Each gem carries its own rich history, distinct geological origins, and captivating symbolism, offering a diverse palette of choices for those born in the final month of the year. This article will delve into the characteristics of each of these December birthstones, exploring their historical significance, gemological properties, and modern appeal.
History and Lore
Turquoise holds the longest-standing claim as a December birthstone, with a history stretching back millennia. As early as the ancient Egyptians, turquoise was prized for its beauty and believed protective qualities. Pharaohs adorned themselves with the gem, and it was incorporated into tombs, signifying a belief in its power to guarantee health and good fortune in the afterlife. Chinese artisans were carving turquoise over 3,000 years ago, demonstrating its widespread appeal across cultures. Throughout the 13th century, turquoise was thought to safeguard against falls, particularly from horses, and was believed to shatter as a warning of impending disaster. Hindu traditions associated viewing turquoise after a new moon with the attainment of great wealth.
Tanzanite, the newest addition to December’s birthstone family, has a comparatively recent history. Discovered in the foothills of Mount Kilimanjaro in Tanzania in the late 1960s by a Maasai tribesman named Jumanne Ngoma, the gem initially resembled sapphire. However, the Gemological Institute of America identified it as a unique variety of zoisite. Tiffany & Co. recognized its potential but faced a marketing challenge: the name “blue zoisite” sounded uncomfortably similar to “blue suicide.” To overcome this, they rebranded the gem as “tanzanite,” honoring its country of origin. Tanzanite was officially added as a December birthstone in 2002.
Zircon also enjoys a long and storied past, though its history is less focused on specific cultural beliefs than turquoise. It is often found alongside sapphire deposits in locations like Sri Lanka, Australia, Myanmar, Vietnam, and Cambodia.
Geological Formation and Sources
Turquoise is a semi-translucent to opaque gem, typically ranging in color from blue to green, often exhibiting veins of matrix – remnants of the rock in which it formed. Its formation occurs in arid regions, often in the presence of copper deposits.
Tanzanite originates from a single, relatively small area near the Merelani Hills of northern Tanzania, at the base of Mount Kilimanjaro. This limited geographical source contributes to its rarity and value. It begins as brownish zoisite, requiring heat treatment to reveal the vibrant blue to violet hues for which it is celebrated.
Zircon is found in a variety of geological settings and is sourced from locations including Sri Lanka and Australia. It can also be found in Myanmar, Vietnam, and Cambodia, often in proximity to sapphire deposits.
Gemological Properties
Each of these December birthstones possesses unique gemological properties. Turquoise is not typically evaluated by the “Four Cs” (cut, clarity, color, carat) in the same way as diamonds. Its value is influenced by the intensity of its color, the fineness of its grain, and the presence of matrix.
Tanzanite, a calcium aluminum silicate, typically ranges from 6 to 7 on the Mohs scale of hardness. This means it is relatively durable but can be susceptible to scratching and abrasion. It exhibits strong trichroism, meaning it displays three different colors – blue, violet, and burgundy – depending on the viewing angle. Most tanzanite undergoes heat treatment to enhance its blue-violet hues, a process that permanently alters the gem’s color without compromising its durability.
Zircon, with a hardness ranging from 6 to 7.5 on the Mohs scale, is also susceptible to abrasion. It is commonly heat-treated to produce blue and colorless varieties, as well as orange, yellow, and red hues. Some heat-treated zircons may revert to their original light brown color after prolonged exposure to bright light, and exposure to heat can alter the color of some stones.
The following table summarizes key gemological properties:
| Gemstone | Chemical Composition | Hardness (Mohs) | Color Range | Notable Characteristics |
|---|---|---|---|---|
| Turquoise | Hydrated Copper Aluminum Phosphate | 5-6 | Blue to Green | Often contains matrix; opaque |
| Tanzanite | Calcium Aluminum Silicate (Zoisite) | 6-7 | Blue, Violet, Burgundy | Trichroic; often heat-treated |
| Zircon | Zirconium Silicate | 6-7.5 | Colorless, Blue, Orange, Yellow, Red | Can revert to brown after light exposure; often heat-treated |
Symbolism and Metaphysical Beliefs
Throughout history, these gemstones have been imbued with symbolic meaning. Turquoise, as previously mentioned, was believed to offer protection, good fortune, and health. It was considered a love charm and a safeguard against evil spirits.
While tanzanite’s history is shorter, it is often associated with transformation, intuition, and spiritual awareness. Its vibrant color is thought to inspire creativity and promote a sense of calm.
Zircon has been linked to prosperity and wisdom. Historically, it was believed to ward off illness and protect travelers.
Care and Cleaning
Proper care is essential to maintain the beauty of these December birthstones. Zircon, due to its tendency to abrade, should be protected from rough wear during activities like gardening, sports, or dishwashing. Turquoise, being relatively soft, is also susceptible to scratches and should be handled with care.
Tanzanite, while relatively durable, can crack if exposed to sudden temperature changes or very high heat. It is best set in earrings or pendants to minimize the risk of damage.
For all three gemstones, cleaning should be performed with a soft brush and mild soap in warm water. Ultrasonic and steam cleaners are not recommended, particularly for tanzanite and zircon.
Conclusion
December’s birthstones – turquoise, tanzanite, and zircon – offer a captivating array of colors, histories, and symbolic meanings. From the ancient protective powers attributed to turquoise to the modern allure of tanzanite and the enduring beauty of zircon, these gems provide a diverse selection for those seeking a meaningful connection to their birth month. Each stone represents a unique facet of the earth’s geological artistry and a rich tapestry of cultural lore, making them treasured possessions for generations to come.