December is unique among the months, boasting not one, but three recognized birthstones: blue zircon, blue topaz, and tanzanite. Alongside the traditional choices of turquoise and lapis lazuli, these gems offer a rich spectrum of color, history, and symbolism for those born in the final month of the year. These stones have been valued for centuries, appearing in royal jewels, ancient artifacts, and modern designs, each possessing a distinct allure and significance.
A History Intertwined with Tradition
The tradition of associating gemstones with specific months dates back to ancient times, though the specific stones assigned have evolved over the centuries. The practice originated in biblical times and gained traction in medieval Europe, where gemstones were believed to possess healing properties and offer protection. While turquoise and lapis lazuli represent the traditional birthstones for December, the modern additions of zircon, topaz, and tanzanite reflect both historical appreciation and more recent discoveries. These colored gems were, and continue to be, blessed to those who wear them in rings, pendants, and other jewelry.
Blue zircon, in particular, has a long and storied past, originating in the Middle East before gaining popularity in Victorian Europe. It was revered for its brilliant blue hues and often adorned royal jewels, becoming a symbol of luxury and prestige. Turquoise, cherished by countless civilizations, including Native Americans and Egyptians, was even incorporated into the burial mask of King Tut, demonstrating its significance in ancient cultures.
Geological Origins and Sources
The geological formation and sources of these December birthstones vary considerably. Turquoise, a hydrated phosphate of copper and aluminum, forms in arid regions through a process of secondary enrichment of copper-bearing rocks. It is commonly found in the southwestern United States, particularly in Arizona, New Mexico, and Nevada, and has been historically sourced from Persia (modern-day Iran).
Zircon, a silicate mineral, is one of the oldest minerals on Earth, with some zircons dating back over four billion years. It is found in a variety of geological settings, including igneous, metamorphic, and sedimentary rocks, and is mined in countries such as Cambodia, Sri Lanka, and Australia. Blue zircon’s color is often achieved through heat treatment.
Tanzanite, a relatively recent discovery, is a blue-violet variety of the mineral zoisite. It is found exclusively in the Merelani Hills of northern Tanzania, near Mount Kilimanjaro, making it a geographically unique gemstone. The most famous tanzanite is known as the “Queen of Kilimanjaro,” a 242-carat masterpiece set with tsavorite garnets and diamonds.
Gemological Properties: A Comparative Look
Each of these December birthstones possesses unique gemological properties that contribute to its beauty and desirability.
| Property | Blue Zircon | Blue Topaz | Tanzanite | Turquoise | Lapis Lazuli |
|---|---|---|---|---|---|
| Chemical Formula | ZrSiO₄ | Al₂SiO₄(OH,F)₂ | Ca₂Al₃(SiO₄)₃(OH) | CuAl₆(PO₄)₄(OH)₈·4H₂O | (Na,Ca)₉Al₆Si₆O₂₄S |
| Hardness (Mohs) | 6.5 - 7.5 | 8 | 6 - 7 | 5 - 6 | 5.5 |
| Color | Various shades of blue | Various shades of blue | Blue, violet-blue | Blue-green | Deep blue |
| Crystal System | Tetragonal | Orthorhombic | Triclinic | Triclinic | Isometric |
| Refractive Index | 1.92 - 1.98 | 1.60 - 1.62 | 1.62 - 1.70 | 1.61 - 1.65 | 1.50 - 1.55 |
Blue zircon is known for its strong “fire,” or dispersion, which gives it a brilliant sparkle. Blue topaz, with a hardness of 8 on the Mohs scale, is a durable gemstone often used in everyday jewelry. Tanzanite exhibits pleochroism, meaning it displays different colors when viewed from different angles, ranging from sapphire blue to violet. Turquoise’s color is influenced by the presence of copper and iron, while lapis lazuli’s deep blue hue comes from sulfur compounds.
Symbolism and Metaphysical Beliefs
Throughout history, these December birthstones have been attributed with various symbolic meanings and metaphysical properties. Turquoise, revered for centuries, is often seen as a talisman for protection and a symbol of good fortune. It is believed to instill inner calm and foster creativity. Lapis lazuli, with its deep azure tones, has long been associated with wisdom and royalty, considered a stone of truth and enlightenment.
Blue zircon is believed to promote wisdom, honor, and prosperity. Tanzanite is thought to possess high-vibration healing energy, acting as a spiritual guide on a path to wisdom and consciousness. It is also associated with manifestation and transformation.
Apache Native Americans believed turquoise could help one’s aim when attached to a bow or firearm, while other tribes used it in jewelry, amulets, and as a medium of exchange.
Care and Cleaning
Proper care is essential to maintain the beauty and luster of December birthstones. Due to its hardness of 6.5 to 7.5 on the Mohs scale, zircon is susceptible to scratching and should be stored carefully. Blue topaz, being harder, is more durable but can still be chipped with a sharp blow. Tanzanite is relatively soft and should be protected from harsh impacts.
Turquoise is porous and can be affected by oils and chemicals, so it should be cleaned with a soft cloth and mild soap and water. Lapis lazuli is also relatively soft and should be handled with care. Generally, all these gemstones can be cleaned with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and harsh chemicals, as they can damage the stones.
Conclusion
December’s birthstones—zircon, topaz, tanzanite, lapis lazuli, and turquoise—offer a captivating blend of history, symbolism, and aesthetic appeal. From the ancient origins of turquoise and lapis lazuli to the more recent discovery of tanzanite, each gemstone holds a unique place in the world of gemology. These stones are more than just beautiful adornments; they connect wearers to cultural narratives and offer a distinct way to express individuality. When choosing between these gemstones, careful research and consultation with experts are recommended to ensure quality and authenticity, allowing the wearer to enjoy their vibrant colors and deep cultural roots for years to come.