December boasts a unique distinction among the months: it possesses not one, but three officially recognized birthstones – turquoise, zircon, and tanzanite. These gemstones, each with its own captivating history, geological origins, and aesthetic qualities, offer a diverse palette of blues and violets for those born in the final month of the year. This article will delve into the characteristics of each of these December birthstones, exploring their historical significance, gemological properties, and cultural associations.
History and Lore
The longest-standing of the December birthstones is turquoise, with a history stretching back nearly 6,000 years. Ancient Egyptians mined turquoise in the Sinai desert, fashioning it into scarab amulets. Persian architects utilized the stone, ground into powder, to adorn mosque domes, a testament to its enduring beauty. In the American Southwest, Navajo silversmiths revered turquoise as “stone fallen from the sky,” believing it held the protective power of thunder gods. Beyond its aesthetic appeal, turquoise was historically believed to guarantee health and good fortune. From the 13th century onward, it was thought to safeguard wearers from falls, even breaking into pieces to warn of impending disaster. Hindu traditions held that viewing turquoise after a new moon would bring immense wealth.
Zircon, while sharing December’s birthstone status, has a history rooted in Persian culture. Its name originates from the Persian word “zargun,” meaning “golden-colored,” reflecting the gem’s original and diverse color range. Throughout history, zircon has symbolized purity and spiritual grounding.
Tanzanite is the newest addition to the December birthstone family, discovered in Tanzania in the 1960s. Its captivating violet-blue hues quickly gained international recognition, and it is now often compared to blue diamonds in terms of color vibrancy. Initially named ‘Blue Zoisite,’ it was later renamed ‘Tanzanite’ in honor of its country of origin.
Geological Formation and Sources
Turquoise is a semi-translucent to opaque gem, typically ranging in color from blue to green, often exhibiting veins of matrix – remnants of the rock in which it formed. Its formation occurs in arid regions, often near copper deposits. Historically significant sources include Egypt’s Sinai desert, Persia, and the American Southwest.
Zircon forms in igneous rocks and alluvial deposits. While it can occur in a variety of colors, the blue varieties used as birthstones are typically produced by heat-treating colorless zircon.
Tanzanite is found exclusively in the Merelani Hills of northern Tanzania, making it a geographically unique gemstone. Its formation is linked to the complex geological processes within this region. The color vibrancy of tanzanite is often compared to blue diamonds, with reflections appearing identical.
Gemological Properties
Each of the December birthstones possesses distinct gemological properties. Turquoise is not a single mineral but a hydrated phosphate of copper and aluminum. It ranges in hardness, typically between 5 and 6 on the Mohs scale.
Zircon boasts a chemical formula of Al2SiO4(F,OH)4 and exhibits a glass-like luster and strong cleavage. While relatively hard, its cleavage makes it somewhat delicate.
Tanzanite, a calcium aluminum silicate, displays a phenomenon known as pleochroism, meaning it exhibits different colors when viewed from different angles. These varying shades of blue, violet, and red contribute to its unique appeal.
Blue topaz, another modern December birthstone, is a silicate mineral composed of aluminum and fluorine. It also exhibits a glass-like luster and deep cleavage. Commercially available blue topaz is often produced by irradiating naturally colorless topaz. Varieties include London Blue (deep inky blue), Swiss Blue (vibrant medium light blue), and Sky Blue (light aqua).
The following table summarizes key gemological properties:
| Gemstone | Chemical Formula | Hardness (Mohs) | Color(s) | Luster |
|---|---|---|---|---|
| Turquoise | Hydrated Phosphate of Copper and Aluminum | 5-6 | Blue to Green | Waxy to Subvitreous |
| Zircon | Al2SiO4(F,OH)4 | 6.5-7.5 | Various, including Blue | Adamantine |
| Tanzanite | Calcium Aluminum Silicate | 6-7 | Violet-Blue | Vitreous |
| Blue Topaz | Al2SiO4(F,OH)4 | 8 | Shades of Blue (London, Swiss, Sky) | Vitreous |
Symbolism and Metaphysical Beliefs
Throughout history, each of these gemstones has been imbued with symbolic meaning. Turquoise is believed to calm nerves and aid in navigation through life’s challenges, making it a traditional talisman for travelers. It is particularly beneficial for those ruled by Jupiter – Pisces and Sagittarius – protecting their energy during risky endeavors.
Zircon has long been associated with purity and spiritual grounding.
Tanzanite is linked to wisdom, peace, and inner strength. Its pleochroism is seen as a reflection of the multifaceted nature of life and the wearer’s vibrant personality.
Care and Cleaning
Due to its relative softness and porous nature, turquoise requires gentle care. Avoid harsh chemicals, ultrasonic cleaners, and prolonged exposure to sunlight. Cleaning can be done with a soft cloth and mild soapy water.
Zircon, while harder than turquoise, is susceptible to chipping along its cleavage planes. Avoid harsh impacts and ultrasonic cleaners. Cleaning can be done with warm soapy water and a soft brush.
Tanzanite is also relatively delicate and should be protected from scratches and harsh chemicals. Cleaning can be done with warm soapy water and a soft brush.
Blue topaz, being a harder gemstone, is more durable but should still be protected from scratches and extreme temperature changes. Cleaning can be done with warm soapy water and a soft brush.
Conclusion
December’s birthstones – turquoise, zircon, and tanzanite – represent a captivating blend of history, beauty, and symbolism. From the ancient protective powers attributed to turquoise to the modern allure of tanzanite and the spiritual grounding of zircon, these gemstones offer a diverse range of options for those seeking a meaningful connection to their birth month. Each stone embodies unique qualities, making them cherished gifts and enduring symbols of elegance and individuality. Understanding the origins, properties, and care of these gems allows for a deeper appreciation of their timeless beauty and cultural significance.