December boasts a remarkable selection of birthstones – turquoise, tanzanite, and zircon – each possessing a unique history, geological origin, and captivating beauty. For centuries, turquoise held prominence as the primary December birthstone, steeped in tradition and lore. More recently, tanzanite and blue zircon have been added to the list, offering a wider spectrum of choices for those born in the final month of the year. This article will delve into the origins, properties, and significance of these three December birthstones, exploring their historical use, geological formation, and the beliefs associated with them.
History and Lore
Turquoise, arguably the oldest of the December birthstones, has a history stretching back millennia. Archaeological evidence suggests its use as far back as 7000 BCE, with discoveries in burial sites in western Iran. Ancient civilizations, including the Egyptians, Chinese, and those of the American Southwest, highly valued this opaque, blue-to-green gem. Egyptians associated turquoise with the goddess Hathor, believing it brought good luck, fertility, and improved a warrior’s accuracy. They fashioned it into amulets, beads, and other small objects. Chinese artisans carved turquoise over 3,000 years ago, while various cultures believed it offered protection from harm, even preventing falls from horses.
While turquoise enjoys a long and storied past, tanzanite is a relatively recent discovery. Found in the Merelani Hills of northern Tanzania in 1967, it was named in honor of its country of origin. A Maasai legend attributes its origin to a bolt of lightning striking the ground, transforming the rocks into shimmering blue stones. The Maasai tribe traditionally gifts tanzanite to new parents as a blessing for health, well-being, and prosperity. Though its history is shorter, tanzanite quickly gained recognition, largely due to the marketing efforts of Tiffany & Co. in 1968.
Zircon also has a long history, though its association with December is more recent. The origin of its name is debated, with some believing it comes from the Sanskrit word “Tapas” meaning “fire,” while others trace it to the Greek word “Topazos,” referring to an island in the Red Sea. Historically, zircon has been valued for its brilliance and range of colors.
Geological Formation and Sources
Turquoise is a semi-translucent to opaque gem formed through a chemical reaction between copper, aluminum, and hydrated phosphate minerals. It often contains veins of matrix, which are remnants of the host rock in which it formed, adding to its unique character. Turquoise deposits are found in various locations around the world, though its historical significance is particularly tied to regions like Iran and the American Southwest.
Tanzanite, a variety of the mineral zoisite, is found exclusively in the Merelani Hills of northern Tanzania. These mines, located near the snow-covered slopes of Mount Kilimanjaro, are the only commercial source of this gemstone. The gem is formed under specific geological conditions involving intense heat and pressure.
Zircon is found in a variety of geological settings, often alongside sapphire deposits. Sources include Sri Lanka, Australia, Myanmar, Vietnam, and Cambodia. It ranges in color from colorless to brown, yellow, orange, and red, with blue varieties being particularly prized. The blue color is often achieved through heat treatment.
Gemological Properties
Each of these December birthstones possesses distinct gemological properties. Turquoise, with a hardness of 5 to 6 on the Mohs scale, is relatively soft and porous. This makes it susceptible to scratching and damage from chemicals. Its color ranges from blue to green, often with matrix inclusions.
Tanzanite typically exhibits a deep, saturated blue to violet color, with blue being the most valuable. It has a hardness of 6.5 to 7 on the Mohs scale, making it more durable than turquoise but still requiring careful handling. Tanzanite displays trichroism, meaning it can show three different colors depending on the viewing angle.
Zircon ranges from 6 to 7.5 on the Mohs scale of hardness. It is commonly heat-treated to produce blue and colorless varieties, as well as orange, yellow, and red hues. While generally stable, heat-treated zircon can sometimes revert to its original color with prolonged exposure to bright light.
Here's a table summarizing the key gemological properties:
| Gemstone | Chemical Formula | Hardness (Mohs) | Color | Transparency |
|---|---|---|---|---|
| Turquoise | CuAl6(PO4)4(OH)8·4H2O | 5-6 | Blue to Green | Opaque |
| Tanzanite | Ca2Al3(SiO4)3(OH) | 6.5-7 | Blue to Violet | Transparent to Translucent |
| Zircon | ZrSiO4 | 6-7.5 | Colorless, Blue, Brown, Yellow, Orange, Red | Transparent |
Symbolism and Metaphysical Beliefs
Throughout history, these gemstones have been attributed with various symbolic meanings and metaphysical properties. Turquoise has long been associated with protection, health, and good fortune. Ancient cultures believed it could ward off evil and guarantee safety.
Tanzanite is often linked to transformation, intuition, and psychic abilities. Some believe it can activate the throat, third-eye, and crown chakras, facilitating communication with higher realms. It is also associated with healing, protection, and self-transformation.
Historically, zircon was believed to strengthen the immune system, detoxify blood, and regenerate cells. It is also associated with prosperity and wisdom.
Care and Cleaning
Proper care is essential to maintain the beauty of these December birthstones. Turquoise, due to its porosity, should be protected from harsh chemicals and impacts. It is best cleaned with a soft brush and mild soap in warm water.
Tanzanite requires careful handling to avoid damage. Avoid sudden temperature changes, extreme heat, and ultrasonic or steam cleaners. Cleaning with a soft brush and warm soapy water is recommended, followed by drying with a soft cloth.
Zircon should also be handled with care, avoiding rough conditions that could cause abrasion. Cleaning can be done with a soft brush and mild soap in warm water. Ultrasonic and steam cleaners are not recommended. Heat-treated zircon should be protected from prolonged exposure to bright light to prevent color fading.
Conclusion
The December birthstones – turquoise, tanzanite, and zircon – offer a captivating array of colors, histories, and symbolic meanings. From the ancient lore surrounding turquoise to the recent discovery and rapid popularity of tanzanite, and the long-standing appreciation for zircon’s brilliance, each gem holds a unique place in the world of gemstones. Whether chosen for their aesthetic appeal, historical significance, or perceived metaphysical properties, these blue-hued gems provide a beautiful and meaningful connection to the month of December.