December is unique among the months, boasting not one, but four recognized birthstones: Tanzanite, Turquoise, Blue Zircon, and Blue Topaz. All four gemstones share a common thread – a beautiful spectrum of blue hues – yet each possesses a distinct history, geological origin, and set of characteristics that make it special. This article will delve into the fascinating world of these December birthstones, exploring their lore, properties, and significance.
A History of Blue December Stones
The association of specific gemstones with months of the year dates back to the biblical breastplate of Aaron, which featured twelve stones representing the tribes of Israel. Over time, different cultures developed their own correspondences between gemstones and months, often influenced by astrological beliefs. While the modern list of birthstones solidified in 1912 by the National Association of Jewelers, the tradition of assigning gemstones to months is ancient.
Turquoise holds the longest history of the four, having been prized for millennia. Ancient Egyptians adorned themselves with it, and Chinese artisans carved it over 3,000 years ago. Turquoise was believed to guarantee health and good fortune, and from the 13th century onward, it was thought to protect wearers from disaster. In the American Southwest, Navajo silversmiths considered turquoise “stone fallen from the sky,” believing it channeled the protection of thunder gods.
Zircon, while also ancient in origin, has seen its association with December become more prominent in recent times. Tanzanite, however, is the newest addition to the December birthstone family, discovered relatively recently in Tanzania. Blue Topaz has long been a popular gemstone, but its formal recognition as a December birthstone is also a more modern development.
Geological Formation and Sources
The origins of these four gemstones are geographically diverse. Turquoise forms in relatively dry, arid regions, often in the vicinity of copper deposits. Significant sources include the United States (particularly Arizona and New Mexico), Iran, and China. The color of turquoise is influenced by the presence of copper and iron, resulting in shades ranging from blue to green.
Tanzanite is exclusively found in a small area near the Mererani Hills of northern Tanzania. It’s a relatively recent discovery, first identified in 1967, and remains a geographically limited gemstone. It begins as brownish zoisite, requiring heat treatment to reveal the sought-after blue to violet hues.
Blue Zircon is sourced from various locations worldwide, including Cambodia, Sri Lanka, and Myanmar. Zircon is a zirconium silicate mineral that naturally occurs in a range of colors, with blue varieties being particularly prized.
Blue Topaz is found in Brazil, Nigeria, and Russia, among other locations. Natural blue topaz is relatively rare; most blue topaz on the market is created through irradiation and heat treatment of colorless topaz.
Gemological Properties
Each of these December birthstones possesses unique gemological properties. Turquoise is a semi-translucent to opaque gem, typically cut into cabochons or beads. Its hardness ranges from 5 to 6 on the Mohs scale, making it relatively soft and susceptible to scratching.
Tanzanite, with a hardness of 6 to 7 on the Mohs scale, is more durable than turquoise but still requires careful handling. It exhibits pleochroism, meaning it displays different colors when viewed from different angles – shades of blue, violet, and red. Most tanzanite undergoes heat treatment to enhance its color, a process that results in a permanent color change. It is best suited for settings in earrings or pendants to minimize the risk of damage.
Blue Zircon boasts a hardness of 6.5 to 7.5 on the Mohs scale, making it more resistant to scratching than both turquoise and tanzanite. It exhibits strong double refraction, which can give it a fiery appearance.
Blue Topaz is the hardest of the four, with a hardness of 8 on the Mohs scale. This makes it a durable gemstone suitable for everyday wear, including in rings. It is relatively resistant to heat and chemicals.
Here's a comparative table of the gemstones' hardness:
| Gemstone | Mohs Hardness |
|---|---|
| Turquoise | 5-6 |
| Tanzanite | 6-7 |
| Blue Zircon | 6.5-7.5 |
| Blue Topaz | 8 |
Symbolism and Metaphysical Beliefs
Throughout history, these gemstones have been imbued with symbolic meanings. Turquoise has long been associated with protection, good fortune, and health. It is believed to calm nerves and is considered a talisman for travelers. For the zodiac signs ruled by Jupiter – Pisces and Sagittarius – turquoise is thought to protect energy and the wearer on challenging journeys.
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.
Blue Zircon is often associated with prosperity and wisdom.
Blue Topaz is believed to promote communication, honesty, and self-confidence.
Care and Cleaning
Proper care is essential to maintain the beauty of these December birthstones. Turquoise, being relatively soft, should be protected from scratches and harsh chemicals. It is best cleaned with a soft cloth and mild soapy water.
Tanzanite requires gentle cleaning with warm, soapy water. Ultrasonic and steam cleaners should be avoided, as they can damage the gemstone. Due to its potential for cracking with sudden temperature changes, tanzanite should not be exposed to extreme heat.
Blue Zircon can be cleaned with warm, soapy water and a soft brush.
Blue Topaz is relatively durable and can be cleaned with warm, soapy water and a soft brush. However, avoid exposing it to sudden temperature changes.
December Birthstone Variations
The association of specific dates within December to each birthstone is a more recent development. Some sources suggest a daily birthstone breakdown, assigning different stones to different days of the month. For example, Blue Topaz is listed as the birthstone for December 4th, 8th, 12th, 16th, 20th, 24th, and 28th, while Tanzanite is associated with the 5th, 9th, 13th, 17th, 21st, 25th, and 29th. Turquoise is linked to the 6th, 10th, 14th, 18th, 22nd, 26th, and 30th, and Blue Zircon to the 7th, 11th, 15th, 19th, 23rd, 27th, and 31st. This detailed breakdown offers a more personalized connection to the birthstones.
Conclusion
The December birthstones – Tanzanite, Turquoise, Blue Zircon, and Blue Topaz – represent a beautiful and diverse collection of gemstones. From the ancient lore of turquoise to the modern discovery of tanzanite, each stone carries a unique history and symbolism. Whether chosen for their aesthetic appeal, metaphysical properties, or personal significance, these blue-hued gems offer a captivating connection to the month of December.