December is unique among the months, boasting not one, but four recognized birthstones: turquoise, blue zircon, tanzanite, and blue topaz. Each of these gemstones presents a distinct shade of blue, mirroring the cool tones of the winter season. While turquoise holds the distinction as the most traditional choice, with a history spanning millennia, tanzanite is the most recent addition, discovered in Tanzania in 1967. These gemstones are associated with meanings of wisdom, protection, and new beginnings, offering December-born individuals a diverse selection to express their individuality. This article will explore the history, geological origins, gemological properties, and symbolism of each of these captivating December birthstones.
A History Rooted in Antiquity: Turquoise
Turquoise’s history is remarkably long, with evidence suggesting its use in jewelry and ornamentation as far back as 7,500 years ago in ancient Egypt. The name “turquoise” itself is believed to originate from the fact that the stone first arrived in Europe via traders from Turkey, referred to as “Turks,” leading the French to call it “pierre tourgues,” or Turkish stone. Mining of turquoise dates back to at least 2100 B.C. in Persia (modern-day Iran), where the material mined there continues to be highly regarded as “Persian turquoise.”
Today, the largest producers of turquoise are the United States – specifically Arizona, New Mexico, and Nevada – and China. Smaller quantities are also mined in Mexico, Afghanistan, Chile, Russia, and Australia. Historically, turquoise has been valued for its spiritual and healing properties, particularly within Hindu traditions, where it is associated with good health and is often set in rings to maintain direct contact with the skin.
The Newest Gem: Tanzanite’s Recent Discovery
In contrast to turquoise’s ancient history, tanzanite is a relatively recent discovery, unearthed in Tanzania during the 1960s and subsequently marketed by Tiffany & Co. This transparent blue crystal is notable for its unique geographical origin; it is found only in a small area near Mount Kilimanjaro and nowhere else in the world. Tanzanite typically exhibits a range of colors from blue to purple, sometimes displaying both hues depending on the viewing angle and lighting conditions due to its strong pleochroism. Like blue zircon, tanzanite is commonly heat-treated to enhance its coloration, bringing out its most attractive shades.
Zircon: A Brilliant, Ancient Gem
Blue zircon is a natural gemstone, distinct from synthetic cubic zirconia, and is found primarily in Thailand, Cambodia, and Vietnam. Zircon occurs in a variety of colors, including golden, red, and clear, with the blue variety being particularly popular. Its high refractive index contributes to its brilliance, historically leading to its use as a diamond substitute.
Interestingly, zircon contains trace amounts of uranium and thorium, making it valuable in radiometric dating. Some zircon specimens have been dated to be as old as 4.4 billion years, making them the oldest minerals ever recorded on Earth. While large zircon specimens are occasionally found, most gems on the market are relatively small.
Blue Topaz: An Affordable and Radiant Alternative
Blue topaz, while not always listed among the traditional December birthstones, is a beloved choice for its icy blue clarity and calming energy. It serves as a popular and more affordable alternative to blue zircon, as it is readily available in larger sizes. Designer-level birthstone selections often feature blue topaz due to its accessibility and attractive appearance.
Gemological Properties: A Comparative Overview
Each of the December birthstones possesses unique gemological properties. Turquoise, a copper aluminum phosphate, forms through the interaction of rainwater with copper ore deposits. It has a Mohs hardness of 5 to 6, making it relatively soft and susceptible to scratching. Tanzanite, a variety of the mineral zoisite, is known for its pleochroism and typically requires heat treatment to achieve its optimal blue-violet coloration. Zircon boasts a high refractive index, contributing to its brilliance, and its age can be determined through radiometric dating. Blue topaz, known for its clarity, is a durable gemstone suitable for everyday wear.
The following table summarizes key properties:
| Gemstone | Chemical Composition | Hardness (Mohs) | Notable Properties |
|---|---|---|---|
| Turquoise | Copper Aluminum Phosphate | 5-6 | Opaque, porous, susceptible to discoloration |
| Tanzanite | Zoisite | 6.5-7 | Pleochroic, often heat-treated |
| Blue Zircon | Zircon | 6.5-7.5 | High refractive index, can be heat-treated |
| Blue Topaz | Aluminum Silicate | 8 | Durable, clear, available in large sizes |
Symbolism and Metaphysical Beliefs
Throughout history, these December birthstones have been attributed with various symbolic meanings and metaphysical properties. Turquoise has long been associated with protection, healing, and good fortune, particularly in Native American cultures. Tanzanite is believed to promote spiritual awareness and transformation. Zircon is thought to enhance wisdom and prosperity, while blue topaz is associated with communication and tranquility. In India, turquoise is specifically linked to the zodiac sign Sagittarius and is believed to promote good health. The tradition of wearing birthstones in direct contact with the skin, as practiced by many Hindus, is believed to maximize their beneficial effects.
Care and Cleaning
Due to their varying hardness and properties, each of these gemstones requires specific care. Turquoise, being relatively soft and porous, should be protected from scratches and harsh chemicals. Cleaning should be done gently with a soft cloth and mild soap. Tanzanite and blue zircon, while more durable, can still be damaged by ultrasonic cleaners and harsh chemicals. Warm, soapy water and a soft brush are recommended for cleaning. Blue topaz is relatively durable and can withstand more rigorous cleaning methods, but it is still advisable to avoid harsh chemicals. Regular cleaning will help maintain the brilliance and beauty of all four December birthstones.
Conclusion
The December birthstones – turquoise, tanzanite, blue zircon, and blue topaz – represent a diverse and captivating collection of gemstones. From the ancient origins of turquoise to the recent discovery of tanzanite, each stone carries a unique history and symbolism. Their varying shades of blue reflect the cool tones of the winter season, while their individual properties offer a range of options for those seeking a meaningful and beautiful gemstone. Whether chosen for their aesthetic appeal, historical significance, or perceived metaphysical benefits, these December birthstones continue to enchant and inspire.