December boasts not one, but two recognized birthstones: Tanzanite and Zircon. Both gems offer a captivating allure, yet they differ significantly in origin, history, and gemological properties. This article will delve into the characteristics of each, exploring their historical context, geological sources, and the symbolism associated with these December birthstones.
A History of December’s Gems
The tradition of associating specific gemstones with birth months has ancient roots, evolving over centuries. While early traditions varied, the modern standardization of birthstones gained momentum in the 20th century. Zircon has a longer history as a December birthstone, while Tanzanite was a more recent addition, gaining official recognition in 2002. The marketing efforts of Tiffany & Co. were instrumental in popularizing Tanzanite, launching a significant advertising campaign in 1968 to introduce the gem to an international audience. This promotion highlighted the gem’s unique beauty and established its place in the gemstone market.
Tanzanite: A Recent Discovery with Rapid Appeal
Tanzanite’s story is relatively recent, as it was first discovered in the Merelani Hills of Tanzania. The gem is named after its country of origin, a practice that underscores its unique geographical connection. Its introduction to the market was swift, largely due to the aforementioned efforts of Tiffany & Co., who recognized its “international appeal.” Tanzanite is now a popular choice for jewelry, frequently gifted to celebrate a 24th wedding anniversary.
Zircon: A Gem with Ancient Lineage
Zircon, in contrast, has a much longer history of use and appreciation. Its name is derived from the Arabic word ‘zargun,’ meaning gold-colored. The gem’s brilliance has been recognized for centuries, and it appears in a wide range of colors, including red, orange, brown, yellow, green, and blue. Historically, blue Zircon has been favored as the December birthstone, though it is now often substituted with blue Topaz due to availability and cost considerations. Zircon is also commonly heat-treated to enhance or alter its color, a practice widely accepted within the gemological community.
Geological Formation and Sources
The geological origins of Tanzanite and Zircon are distinct. Tanzanite is found exclusively in the Merelani Hills of Tanzania, making it a geographically limited gemstone. This rarity contributes to its value and desirability. Zircon, however, is sourced from a wider range of locations, including Sri Lanka and Australia. Additional sources include Vietnam, Mozambique, Pakistan, and Madagascar. The varied geological environments in which Zircon forms contribute to its diverse color range.
Gemological Properties: A Detailed Comparison
Both Tanzanite and Zircon possess unique gemological properties that contribute to their beauty and durability.
Tanzanite:
- Color: Typically exhibits a vivid violet-blue hue.
- Hardness: Ranks between 6 and 7 on the Mohs scale.
- Resistance: Resistant to heat, light, and common chemicals.
- Clarity: Known for its high clarity and vivid colors.
- Usage: Best suited for earrings or pendants due to its relative softness.
Zircon:
- Color: Available in a wide spectrum of colors, including red, orange, brown, yellow, green, and blue.
- Hardness: Ranges from 6 to 7.5 on the Mohs scale.
- Treatment: Commonly heat-treated to produce different color varieties.
- Durability: Can be used in everyday jewelry if properly treated.
The Mohs scale of hardness provides a comparative measure of a mineral’s resistance to scratching. A higher number indicates greater hardness. The following table illustrates the relative hardness of Tanzanite and Zircon compared to other common materials:
| Material | Mohs Hardness |
|---|---|
| Talc | 1 |
| Gypsum | 2 |
| Calcite | 3 |
| Fluorite | 4 |
| Apatite | 5 |
| Zircon | 6 - 7.5 |
| Tanzanite | 6 - 7 |
| Quartz | 7 |
| Topaz | 8 |
| Corundum | 9 |
| Diamond | 10 |
Symbolism and Metaphysical Beliefs
Throughout history, gemstones have been imbued with symbolic meanings and metaphysical properties. While the sources do not detail extensive metaphysical beliefs specifically tied to Tanzanite and Zircon, some general associations can be inferred. Zircon, with its long history, was believed to promote harmony and was thought to cure blood loss and inflammatory diseases. Peridot, another birthstone, was used as a protective talisman for centuries. Aquamarine, the March birthstone, is associated with tranquility and a happy marriage. The clear blue color of Aquamarine, reminiscent of seawater, led to legends connecting it to mermaids and the power of Neptune, offering protection to sailors. Diamonds, the April birthstone, symbolize purity and enduring beauty, and were historically used in medicine by royalty and religious leaders.
Care and Cleaning
Proper care is essential to maintain the beauty and integrity of both Tanzanite and Zircon. Due to their moderate hardness (6-7.5 on the Mohs scale), both gems are susceptible to scratching. It is advisable to avoid wearing jewelry containing these stones during strenuous activities. Cleaning should be performed with mild soap and warm water, using a soft brush to remove any dirt or debris. Opal, another birthstone, requires particularly careful cleaning with soapy water to prevent damage. Zircon, being relatively durable, can be used in everyday jewelry with appropriate care. Tanzanite, due to its slightly lower hardness, is best suited for earrings or pendants to minimize the risk of abrasion.
Zodiac Birthstones: A Broader Perspective
The concept of zodiac birthstones adds another layer to the tradition of associating gems with specific times of the year. Ancient and medieval astrologers believed that gemstones reflected the influence of the planets and constellations, connecting individuals to the heavens. While standard birthstones often include precious gems, zodiac birthstones frequently feature semi-precious stones. For example, Aries is associated with Red Jasper, Taurus with Rose Quartz, and Gemini with Tiger’s Eye. This system offers a more personalized approach to gemstone selection, based on an individual’s astrological sign.
Conclusion
December’s birthstones, Tanzanite and Zircon, represent a fascinating duality. Tanzanite, a relatively recent discovery, embodies rarity and modern elegance, while Zircon carries a legacy of ancient lore and enduring brilliance. Both gems offer unique beauty and symbolism, making them cherished gifts and meaningful adornments. Understanding their geological origins, gemological properties, and historical context enhances the appreciation for these captivating December birthstones.