December is unique among the months, possessing not one, but four recognized birthstones: Turquoise, Blue Zircon, Tanzanite, and Blue Topaz. Historically, the designation of birthstones has varied across cultures and time periods, with Lapis Lazuli, Chrysoprase, Onyx, and even Ruby holding significance as December stones in different traditions. This rich variety reflects the enduring human fascination with colored gems and the beliefs surrounding their metaphysical properties. This article will explore the history, geological origins, gemological characteristics, and symbolism of these December birthstones, drawing upon available information to provide a comprehensive overview.
A History of December’s Stones
The tradition of associating specific gemstones with months of the year dates back to ancient times, though the specific stones assigned have evolved. Turquoise holds the distinction of being one of the oldest known birthstones, with a history stretching back millennia. Its name originates from the French phrase ‘pierre turquoise,’ meaning “stone of Turkey,” reflecting the historical trade routes through which the gem reached Europe from Turkish bazaars.
Zircon, while now a prominent December birthstone, replaced Lapis Lazuli as the primary stone in the United States in 1952. Lapis Lazuli itself held the position until then, and was considered a birthstone for December as recently as 2013, when the American Gem Trade Association made the change. Historically, Ruby was also considered a December birthstone in Arabic, Hebrew, Italian, Roman, and Indian traditions, linked to the zodiac sign of Capricorn, which partially falls within December.
Tanzanite is a more recent addition to the December birthstone family, discovered in Tanzania in 1967 and officially recognized as a December stone in Britain before its adoption in the United States in 2002. Other stones, like Chrysoprase and Onyx, were designated as December birthstones in older Russian and Tibetan calendars, respectively.
Geological Formation and Sources
The origins of these December birthstones are as diverse as the stones themselves. Turquoise is a hydrated phosphate of copper and aluminum, forming in relatively dry, arid environments. It is often found in association with copper deposits, and significant sources include the United States, Iran, and Turkey.
Zircon forms in igneous rocks and alluvial deposits, occurring in a wide range of colors. Blue zircon, the variety most commonly associated with December, is often created through heat treatment of colorless or brown zircon. Sources include Cambodia, Sri Lanka, and Myanmar.
Tanzanite, a relatively recent discovery, is found exclusively in the Merelani Hills of northern Tanzania, hence its name. It is a blue to purple variety of the mineral zoisite.
Blue Topaz, another December birthstone, is a silicate mineral of aluminum and fluorine. It is found in igneous rocks and is sourced from locations like Brazil, Sri Lanka, and Nigeria.
Gemological Properties
Each December birthstone possesses unique gemological properties that contribute to its beauty and desirability.
Turquoise: This opaque gemstone typically ranges in color from sky-blue to greenish-blue, though it can also be found in shades of green and even black. Its hardness on the Mohs scale is relatively low, ranging from 5 to 6, making it susceptible to scratching.
Blue Zircon: Zircon boasts a high refractive index, giving it exceptional brilliance and sparkle, often mistaken for diamond. It has a hardness of 6.5 to 7.5 on the Mohs scale. Blue zircon is often created by heat-treating naturally colored zircon.
Tanzanite: This gemstone exhibits strong trichroism, meaning it displays three different colors – blue, violet, and burgundy – depending on the viewing angle. Its hardness is between 6 and 7 on the Mohs scale.
Blue Topaz: Topaz is a relatively hard gemstone, with a Mohs hardness of 8. Blue topaz is often created through irradiation and heat treatment of colorless topaz.
Here's a table summarizing the key properties:
| Gemstone | Chemical Composition | Hardness (Mohs) | Color(s) | Transparency |
|---|---|---|---|---|
| Turquoise | Hydrated Phosphate | 5-6 | Blue, Green, Black | Opaque |
| Blue Zircon | Zirconium Silicate | 6.5-7.5 | Blue | Transparent |
| Tanzanite | Calcium Aluminum Silicate | 6-7 | Blue, Violet, Burgundy | Transparent |
| Blue Topaz | Aluminum Fluorosilicate | 8 | Blue | Transparent |
Symbolism and Metaphysical Beliefs
Throughout history, each of these December birthstones has been attributed with various symbolic meanings and metaphysical properties. Turquoise is often associated with success, happiness, and prosperity. It is believed to support the immune system and aid in detoxification.
Blue Zircon is thought to bring peace of mind and prosperity, enhancing both physical and spiritual strength. Tanzanite is believed to improve skin and hair health, fostering compassion and calmness.
Lapis Lazuli, a former December birthstone, was believed to heighten awareness, expand perspective, and free a person of negativity. Chrysoprase was thought to enhance emotional balance and prevent depression, while Onyx was considered a grounding stone offering protection from negativity. Ruby, historically linked to December, was believed to strengthen the mind and bestow courage.
Care and Cleaning
Proper care is essential to maintain the beauty of these December birthstones. Turquoise, due to its relative softness, is susceptible to scratching and should be protected from harsh impacts. It is best cleaned with a soft cloth and mild soap and water.
Zircon and Tanzanite require gentle cleaning with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and harsh chemicals, as these can damage the stones. Blue Topaz is relatively durable but should still be handled with care. Avoid sudden temperature changes, as these can cause fractures.
Conclusion
December’s birthstones – Turquoise, Blue Zircon, Tanzanite, and Blue Topaz – represent a captivating blend of history, geological wonder, and symbolic meaning. From ancient traditions to modern discoveries, these gems continue to enchant and inspire. The variety of options available allows individuals born in December to choose a stone that resonates with their personal style and beliefs, carrying with them a piece of the earth’s beauty and a connection to centuries of tradition.