December is unique among the calendar months, boasting not one, but three recognized birthstones: turquoise, tanzanite, and zircon. While turquoise holds the most consistent historical association with the month, the inclusion of tanzanite and zircon reflects the evolving nature of birthstone lists and offers December-born individuals a diverse selection of beautiful and meaningful gems. This article will delve into the history, geological origins, gemological properties, and cultural significance of each of these December birthstones, providing a comprehensive overview for gemstone enthusiasts and those seeking to understand the lore surrounding these captivating jewels.
A History of December’s Gems
The designation of birthstones has a long and complex history, evolving over centuries and across cultures. Early associations were often linked to religious texts and the breastplate of Aaron, with specific gemstones assigned to each of the twelve tribes of Israel. Initially, ruby was linked to December, but over time, this association shifted. The modern birthstone list began to take shape in the 19th and 20th centuries, with various jewelry trade organizations contributing to the evolving standards.
Turquoise has the longest and most consistent history as a December birthstone, appearing as early as 1870 in Tiffany & Co.’s birthstone pamphlets. By 1912, it was firmly established as the primary December birthstone, often accompanied by lapis lazuli as an alternative. Zircon was added to the list in 1952, and tanzanite, the newest addition, was officially recognized in 2002. This progression demonstrates how birthstone lists are not static, but rather reflect changing tastes, discoveries, and marketing influences.
Turquoise: A Stone of Protection and Victory
Turquoise, with its captivating blue-green hues, is arguably the most iconic of December’s birthstones. Its name derives from the French phrase “pierre turquoise,” meaning “Turkish stone,” as the material often entered Europe through Turkey. However, the gem’s origins lie much further afield, with significant sources in Persia (now Iran), Egypt, and the American Southwest.
Historically, turquoise has been revered by numerous cultures. Ancient Egyptians mined turquoise as early as 3000 BC, calling it mefkat, meaning “joy,” and associating it with the sky goddess Hathor. They used it for protection and status, incorporating it into jewelry and funerary objects. In ancient Persia, turquoise, known as pērōzah (“victory”), was considered a sacred stone, believed to be a fragment of the heavens. It was frequently set into turbans, weapons, and mosques. Aztecs viewed turquoise as sacred, believing it embodied fire and associating it with the deity Quetzalcoatl, even burying rulers with turquoise in their mouths. Native American tribes also held turquoise in high esteem, utilizing it in ceremonial items, talismans, and as a form of currency. The Apache tribe believed attaching turquoise to bows ensured accurate aim.
Geologically, turquoise is a copper aluminum phosphate, formed through chemical reactions between copper-bearing minerals and rainwater percolating through rock. The blue color is attributed to the presence of copper, while iron contributes to green hues. The veined appearance often seen in turquoise is due to remnants of the host rock.
Tanzanite: A Modern Marvel
Tanzanite is a relatively recent discovery, first identified in Tanzania in 1967. Its captivating blue-violet color quickly gained popularity, leading to its inclusion as a December birthstone in 2002. Tanzanite is a variety of the mineral zoisite, and most rough material is brownish in color. Heat treatment is essential to reveal the vibrant blue to violet hues that characterize this gem. This color change is permanent, and does not affect the stone’s durability.
Tanzanite is found in a small area near the Mererani Hills of northern Tanzania, making it a geographically limited gemstone. This scarcity contributes to its value and desirability. With a hardness of 6 to 7 on the Mohs scale, tanzanite is relatively soft and susceptible to scratching. It is best suited for settings in earrings or pendants, and requires careful handling when worn in rings. Cleaning should be done with warm, soapy water; ultrasonic and steam cleaners are not recommended.
Zircon: A Brilliant Blue
Zircon, often confused with cubic zirconia, is a naturally occurring gemstone with a long history of use in jewelry. While it comes in a variety of colors, blue zircon is the most commonly associated with December. Zircon is known for its brilliance and high refractive index, giving it a sparkling appearance.
Zircon has been mined for centuries, with ancient sources in Sri Lanka and Southeast Asia. Historically, zircon was used as a diamond simulant, prized for its fire and luster. The name “zircon” is believed to be derived from the Persian word zargun, meaning “gold-colored.”
Zircon’s chemical composition is zirconium silicate. It registers a hardness of 6.5 to 7.5 on the Mohs scale, making it reasonably durable for jewelry use. However, it can be brittle and susceptible to cleavage, requiring careful handling and protective settings.
Gemological Properties Compared
The three December birthstones exhibit distinct gemological properties. The following table summarizes key characteristics:
| Property | Turquoise | Tanzanite | Zircon |
|---|---|---|---|
| Chemical Formula | CuAl6(PO4)4(OH)8·4H2O | Ca2Al3(SiO4)3(OH) | ZrSiO4 |
| Color | Blue to Green | Blue to Violet | Colorless to Blue |
| Hardness (Mohs) | 5-6 | 6-7 | 6.5-7.5 |
| Transparency | Opaque | Transparent | Transparent |
| Refractive Index | N/A | 1.619 – 1.688 | 1.810 – 2.024 |
| Specific Gravity | 2.60 – 2.80 | 3.35 – 3.53 | 3.93 – 4.73 |
Symbolism and Metaphysical Beliefs
Each of these December birthstones carries its own set of symbolic meanings and metaphysical beliefs. Turquoise is often associated with protection, healing, and good fortune. It is believed to promote inner calm and foster creativity. Tanzanite is thought to enhance intuition, spiritual awareness, and transformation. Blue zircon is associated with wisdom, prosperity, and honor.
Throughout history, these stones have been used for various purposes, from amulets and talismans to decorative objects and jewelry. Their enduring appeal lies not only in their beauty but also in the beliefs and traditions surrounding them.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of these December birthstones. Turquoise is relatively soft and porous, requiring gentle cleaning with a soft cloth and mild soap. Avoid harsh chemicals and ultrasonic cleaners. Tanzanite should be cleaned with warm, soapy water and should not be exposed to ultrasonic or steam cleaners. Zircon can be cleaned similarly, but due to its potential for brittleness, avoid sudden temperature changes.
Conclusion
December’s trio of birthstones – turquoise, tanzanite, and zircon – offers a rich tapestry of history, geological wonder, and cultural significance. From the ancient reverence for turquoise to the modern allure of tanzanite and the timeless brilliance of zircon, these gems represent a diverse and captivating selection for those born in the final month of the year. Each stone possesses unique properties and symbolism, making them cherished heirlooms and meaningful expressions of personal style.