December boasts a unique distinction among the months: it is associated with not one, but three recognized birthstones – Tanzanite, Zircon, and Turquoise – alongside Blue Topaz as an astrological stone. These gemstones, each with its own history, characteristics, and symbolism, offer a diverse range of options for those born in the final month of the year. This article will explore the origins, properties, and significance of these December birthstones, drawing upon available historical and gemological information.
History and Lore
The tradition of associating specific gemstones with birth months dates back to ancient times, with early connections found in religious texts and ancient cultures. These early associations laid the groundwork for the modern practice of linking gems to particular times of the year. Gemstones were often believed to possess special properties, offering luck, health, and prosperity to their wearers.
While the concept of birthstones evolved over centuries, December’s selection reflects both traditional and more recent additions to the birthstone canon. Turquoise and Zircon have long-standing associations with the month, while Tanzanite is a relatively recent addition, gaining prominence in the 20th century. Blue Topaz is also recognized as an astrological stone for the Sagittarius and Capricorn zodiac signs that fall within December.
Geological Formation and Sources
The origins of these December birthstones vary significantly. Turquoise, as its name suggests, has been prized for its vibrant color for centuries. It is a hydrated phosphate of copper and aluminum, formed in arid regions through the interaction of copper-rich groundwater with volcanic rock. Historically, Persia (modern-day Iran) was a primary source of turquoise, and the gem derives its name from the French phrase "pierre turquoise," meaning "Turkish stone," as the material entered Europe through Turkey. Today, significant deposits are also found in the United States, particularly in Arizona, as well as in China and other parts of the world.
Zircon, a silicate of zirconium, is found in a variety of geological settings, including igneous, metamorphic, and sedimentary rocks. It occurs as a common mineral in many parts of the world, with notable sources including Cambodia, Sri Lanka, and Australia. The color of zircon can range from colorless to brown, red, yellow, and blue. The blue varieties are often produced through heat treatment of colorless zircon.
Tanzanite, discovered in the Merelani Hills of northern Tanzania in 1967, is a relatively recent addition to the gemstone world. It is a blue to violet variety of the mineral zoisite. Its unique trichroism – displaying three different colors depending on the viewing angle – contributes to its captivating appearance. Tanzania remains the sole commercially significant source of tanzanite.
Gemological Properties
Each of these birthstones possesses distinct gemological properties. Turquoise, with a hardness of 5 to 6 on the Mohs scale, is relatively soft and porous, requiring careful handling and protection. Its color ranges from sky blue to greenish-blue, often with matrix (veins of the surrounding rock) visible within the stone.
Zircon exhibits a hardness of 6.5 to 7.5 on the Mohs scale, making it more durable than turquoise. Its refractive index is high, contributing to its brilliance. As mentioned previously, zircon occurs in a wide range of colors, with blue zircon being particularly popular.
Tanzanite, with a hardness of 6 to 7 on the Mohs scale, is also relatively durable. It displays strong pleochroism, meaning it exhibits different colors when viewed from different directions. Its refractive index is relatively high, giving it a vibrant sparkle. Tanzanite’s color is often enhanced through heat treatment, which intensifies its blue and violet hues.
Here's a table summarizing the key properties:
| Gemstone | Chemical Composition | Hardness (Mohs) | Color | Primary Sources |
|---|---|---|---|---|
| Turquoise | Hydrated phosphate of copper and aluminum | 5-6 | Sky blue to greenish-blue | Iran, USA (Arizona), China |
| Zircon | Silicate of zirconium | 6.5-7.5 | Colorless, brown, red, yellow, blue | Cambodia, Sri Lanka, Australia |
| Tanzanite | Calcium aluminum silicate (Zoisite) | 6-7 | Blue to violet | Tanzania |
Symbolism and Metaphysical Beliefs
Throughout history, these gemstones have been attributed with various symbolic meanings and metaphysical properties. Turquoise has long been considered a protective stone, believed to ward off negative energy and bring good fortune. It has been associated with strength, healing, and spiritual grounding.
Zircon, historically, was believed to offer protection to travelers and safeguard loved ones. More recently, it has come to symbolize love and affection. Blue Topaz, also associated with December, is often seen as a stone of communication and self-expression.
Tanzanite, being a more recently discovered gemstone, has developed its own set of associated beliefs. It is often linked to transformation, intuition, and spiritual awareness. Some believe it can facilitate communication with higher realms and promote a sense of calm and clarity.
Care and Cleaning
Due to their varying hardness and properties, each of these birthstones requires specific care. Turquoise, being relatively soft and porous, should be protected from scratches and harsh chemicals. It is best cleaned with a soft cloth and mild soapy water. Avoid ultrasonic cleaners and steam cleaners, as they can damage the stone.
Zircon, being more durable, can be cleaned with warm soapy water and a soft brush. However, avoid harsh chemicals and ultrasonic cleaners, especially for heat-treated stones, as the heat treatment can be reversed.
Tanzanite, while relatively durable, is susceptible to damage from sudden temperature changes. It should be cleaned with warm soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaners.
Conclusion
The December birthstones – Tanzanite, Zircon, and Turquoise – represent a captivating blend of history, beauty, and symbolism. From the ancient origins of Turquoise to the modern discovery of Tanzanite, these gemstones offer a diverse range of options for those born in December. Each stone possesses unique gemological properties and is associated with distinct meanings and beliefs, making them treasured gifts and meaningful adornments. The selection of a December birthstone is a personal one, reflecting individual preferences and the desired symbolism.