December boasts not one, but two recognized birthstones: blue zircon and turquoise. Both gems carry rich histories, unique geological origins, and distinct symbolic meanings. While turquoise has a long and storied past as a protective and healing stone, blue zircon’s vibrant color is a relatively modern development, born from ingenious color-improvement techniques in the 20th century. This article will explore the history, geological sources, gemological properties, and cultural significance of these two December birthstones, drawing solely from available sources.
History and Lore
Turquoise has a particularly long and well-documented history, with evidence of its use dating back millennia. The Aztecs mined turquoise in the area now known as New Mexico, and significant deposits continue to be found in Arizona, California, and Nevada in the United States. Historically, the most prized turquoise originated from Iran (Persia), though contemporary specimens from the southwestern United States are now considered competitive in quality. Throughout history, turquoise has been associated with protection, healing, and good fortune.
Blue zircon’s history is more nuanced. While zircon itself has been known for centuries, the vibrant blue variety is a relatively recent phenomenon. Prior to the 1920s, zircon typically presented in shades of brown or green. The emergence of strikingly brilliant blue zircons in the market during this period initially raised suspicions, as the color was not naturally occurring. Investigations revealed that local entrepreneurs in Siam (Thailand) had developed a method of heating brown zircon in an oxygen-free environment, transforming it into the now-popular blue hue. Despite the discovery of this color-improvement process, the market readily accepted the blue zircon, and demand continued to grow.
Geological Formation and Sources
Turquoise is formed relatively close to the Earth’s surface, in arid regions, through a chemical reaction involving copper, aluminum, and hydrated phosphate minerals. It is commonly found in association with copper deposits. Mining locations include the United States, Mexico, Iran, Chile, China, and Tibet.
Zircon, on the other hand, is found in a wider range of geological settings. Deposits have been identified in Brazil, Afghanistan, Australia, Myanmar (Burma), China, Germany, Japan, Madagascar, Mexico, Namibia, Nigeria, Pakistan, Russia, Zimbabwe, Sri Lanka, Ukraine, and the USA. Notably, natural light-blue zircon is found in Northern Ireland and the UK, though the blue zircons commonly available today are heat-treated.
Gemological Properties
Turquoise is not a crystalline quartz, but rather a hydrated phosphate of copper and aluminum. It is often dyed and stabilized with resins to enhance its color and durability, as the natural stone can be relatively soft and prone to cracking.
Blue zircon is a silicate mineral with a chemical composition of ZrSiO4. It measures 6.5 to 7.5 on the Mohs hardness scale, making it reasonably durable for jewelry use. Zircon exhibits strong double refraction, which contributes to its brilliance. The creation of the blue color in zircon is achieved through heat treatment, altering the stone’s appearance without changing its fundamental chemical composition.
The following table summarizes key gemological properties where available:
| Gemstone | Chemical Composition | Hardness (Mohs) | Color | Notable Characteristics |
|---|---|---|---|---|
| Turquoise | Hydrated phosphate of copper and aluminum | Not specified | Typically blue-green, but can vary | Often dyed and stabilized |
| Blue Zircon | ZrSiO4 | 6.5 - 7.5 | Blue (heat-treated) | Strong double refraction |
Symbolism and Metaphysical Beliefs
Turquoise has long been associated with protective qualities. It was believed to shield wearers from injury and was considered a stone of good fortune. In Middle Eastern cultures, turquoise was presented to couples to ensure fertility and a happy family. It is also linked to love and harmony.
While specific metaphysical beliefs surrounding blue zircon are less detailed in the provided sources, zircon in general has been linked to prosperity and wisdom. The Romans believed zircon was a solid ray of moonlight, filled with good fortune.
Care and Cleaning
The provided sources do not offer specific care and cleaning instructions for either turquoise or blue zircon. However, given turquoise’s tendency to be porous and often stabilized with resin, it is likely best to avoid harsh chemicals and abrasive cleaners. Zircon’s hardness suggests it is more durable, but still requires careful handling to avoid scratches or damage.
Conclusion
Blue zircon and turquoise represent a fascinating pairing of birthstones for December. Turquoise, with its ancient origins and enduring symbolism, embodies protection, healing, and good fortune. Blue zircon, a product of 20th-century ingenuity, showcases the transformative power of gemological treatment and offers a vibrant alternative. Both stones, in their unique ways, contribute to the rich and diverse world of gemstones.