December is unique among the months, boasting not one, but four officially recognized birthstones: Turquoise, Blue Zircon, Tanzanite, and Blue Topaz. Historically, Lapis Lazuli also held significance as a traditional December gem. This abundance offers a diverse palette of color, price points, and symbolic meanings for those born in the final month of the year. The tradition of associating specific gemstones with each month dates back to ancient times, evolving from biblical connections and early cultural practices into the modern birthstone system we know today. These colored gems were, and continue to be, believed to bestow blessings upon the wearer, adorning rings, pendants, and other jewelry.
A History of December’s Gems
The story of December birthstones is a rich tapestry woven through centuries of human history. Turquoise and Zircon have long been considered primary gems for this month, their cool blue hues mirroring the chill of winter. Turquoise, one of the oldest known birthstones, derives its name from ‘pierre turquoise,’ meaning ‘stone of Turkey,’ reflecting its historical trade route through Turkish bazaars into Europe. Lapis Lazuli, with its deep azure tones, was similarly valued in ancient civilizations for its association with wisdom and royalty, considered a stone of truth and enlightenment.
More recently, Tanzanite joined the ranks of December birthstones, discovered only in the late 20th century near Mount Kilimanjaro in Tanzania. Its unique blue to violet color and limited source quickly established it as a highly prized gem. Blue Zircon, often mistaken for diamond due to its brilliance, also holds a significant place, celebrated for its fire and rainbow of colors as one of the oldest minerals on Earth. The addition of multiple stones over time reflects the expansion of gemstone markets and a desire to offer consumers a wider range of choices.
Geological Formation and Sources
The origins of these December birthstones are as diverse as the stones themselves. Turquoise forms in relatively dry, arid regions, often in the vicinity of copper deposits. It is a secondary mineral, meaning it forms as a byproduct of other geological processes, typically through the weathering of copper-rich rocks.
Zircon, a remarkably durable mineral, is found in a variety of igneous and metamorphic rocks. Its formation involves complex geological processes occurring deep within the Earth’s crust. Blue Zircon’s color is often achieved through heat treatment.
Tanzanite, uniquely, is found in only one location worldwide: the Merelani Hills of northern Tanzania, near Mount Kilimanjaro. This limited source contributes to its rarity and value. It forms within metamorphic rocks, created by intense heat and pressure.
Blue Topaz, while not as exclusively tied to one location as Tanzanite, is found in various parts of the world, including Brazil, Nigeria, and Russia. It typically forms in igneous rocks, often within pegmatites – coarse-grained igneous rocks.
Gemological Properties
Each December birthstone possesses distinct gemological properties that contribute to its beauty and desirability.
Turquoise: This opaque gemstone is a hydrated phosphate of copper and aluminum, with a hardness of 5-6 on the Mohs scale. Its color ranges from sky blue to greenish-blue, often with matrix (veins of the surrounding rock) visible within the stone.
Blue Zircon: With a hardness of 6.5-7.5 on the Mohs scale, Blue Zircon is a zirconium silicate. It exhibits strong double refraction, contributing to its brilliance and fire. Its color can range from pale sky blue to deep sapphire blue.
Tanzanite: A calcium aluminum silicate, Tanzanite boasts a hardness of 6-7 on the Mohs scale. It is pleochroic, meaning it displays different colors when viewed from different angles – typically blue, violet, and burgundy.
Blue Topaz: This silicate mineral has a hardness of 8 on the Mohs scale, making it relatively durable. Its color, ranging from pale sky blue to London blue, is often achieved through irradiation and heat treatment.
Here's a comparative table of hardness:
| Gemstone | Mohs Hardness |
|---|---|
| Turquoise | 5-6 |
| Blue Zircon | 6.5-7.5 |
| Tanzanite | 6-7 |
| Blue Topaz | 8 |
Symbolism and Metaphysical Beliefs
Throughout history, December birthstones have been imbued with various symbolic meanings and metaphysical properties. Turquoise has long been revered as a talisman for protection and a symbol of good fortune, instilling a sense of inner calm and fostering creativity. Lapis Lazuli, with its deep blue color, was associated with wisdom, royalty, and a connection to higher consciousness, believed to enhance intellectual abilities.
Blue Zircon is celebrated for its brilliance and clarity, representing prosperity and wisdom. Tanzanite, a more modern addition, is believed to promote communication and intuition. Blue Topaz is often associated with serenity and calmness.
These stones are more than just beautiful adornments; they are believed to reflect the wearer’s personality and connect them to historical and cultural narratives.
Care and Cleaning
Proper care is essential to maintain the beauty of December birthstones. Turquoise, being relatively soft, is susceptible to scratches and should be protected from harsh impacts. Cleaning can be done with a soft cloth and mild soapy water. Avoid ultrasonic cleaners and harsh chemicals.
Blue Zircon, with its good hardness, is more durable but can still be chipped with a sharp blow. Cleaning can be done similarly to Turquoise.
Tanzanite, while relatively durable, is sensitive to heat and sudden temperature changes. Avoid prolonged exposure to sunlight and ultrasonic cleaners. Gentle cleaning with warm, soapy water is recommended.
Blue Topaz, being quite hard, is relatively resistant to scratches. However, it should still be protected from harsh impacts. Cleaning can be done with warm, soapy water and a soft brush.
Conclusion
December’s birthstones – Turquoise, Blue Zircon, Tanzanite, and Blue Topaz – offer a captivating array of colors, histories, and symbolic meanings. From the ancient allure of Turquoise and Lapis Lazuli to the modern discovery of Tanzanite, these gems represent a rich blend of tradition and contemporary appeal. Whether chosen for their aesthetic beauty, perceived metaphysical properties, or personal significance, these radiant stones provide a unique and meaningful connection for those born in the twelfth month of the year. Their diverse traits demand thoughtful handling and care to maintain their beauty over time, ensuring they remain cherished possessions for generations to come.