December boasts a unique distinction among the months: it has not one, but three recognized birthstones – turquoise, zircon, and the more recently added tanzanite. Each gem offers a distinct appeal, ranging in color, history, and geological origin. This article will explore the characteristics, lore, and significance of these December birthstones, drawing upon available information to provide a comprehensive overview for enthusiasts and those seeking to understand the gems’ enduring allure.
History and Lore
Turquoise holds the longest history of the three, having been cherished for millennia. Ancient Egyptians, including pharaohs, adorned themselves with turquoise, believing it possessed protective qualities and guaranteed health and good fortune. Its use extended to ancient China, where artisans carved the stone over 3,000 years ago. Throughout the 13th century, it was thought to safeguard against falls, particularly from horseback, and was believed to fracture as a warning of impending disaster. Hindu traditions associated viewing turquoise after a new moon with the attainment of great wealth.
Zircon, while also ancient in origin, has a less documented early history compared to turquoise. It is often found alongside sapphire deposits in locations like Sri Lanka, Myanmar, Vietnam, and Cambodia.
Tanzanite is the youngest of the three in terms of discovery and recognition. Identified as the mineral zoisite in 1962, its primary source was located in the Merelani Hills of Tanzania in 1967, leading to its naming in honor of the country. Tiffany & Co. played a pivotal role in popularizing tanzanite, launching a major advertising campaign in 1968 that highlighted its vivid colors and clarity. It quickly gained recognition, becoming not only a December birthstone but also the gemstone associated with the 24th wedding anniversary.
Geological Formation and Sources
Turquoise is a semi-translucent to opaque gem, typically ranging in color from blue to green, often exhibiting veins of matrix – remnants of the rock in which it formed. The sources for turquoise are not detailed in the provided materials.
Zircon’s formation and sources are also not extensively detailed. The provided sources indicate it ranges from 6 to 7.5 on the Mohs scale of hardness and is commonly heat-treated to produce various colors.
Tanzanite, however, has a remarkably specific origin. It is found exclusively in the Merelani Hills of northern Tanzania. Mining operations in this region involve digging over 100 meters deep into the earth, with the backdrop of Mount Kilimanjaro’s snow-covered slopes. The landscape surrounding the mines is characterized by grass-covered hillsides, scrub brush, and rocky soil. The provided materials suggest that tanzanite production may be limited, with estimates ranging from 15 to 30 years, though some sources suggest this timeframe may be influenced by the publicly traded status of mining companies.
Gemological Properties
The provided sources offer varying levels of detail regarding the gemological properties of each stone.
Turquoise: Described as semi-translucent to opaque, ranging from blue to green, and often containing matrix. No chemical formula or specific gravity is provided.
Zircon: Ranging from 6 to 7.5 on the Mohs scale of hardness. It is commonly heat-treated to produce blue, colorless, orange, yellow, and red varieties. The gem is stable when exposed to light and chemicals, though heat treatment can sometimes be reversed with prolonged light exposure, causing a return to a light brown color. Prolonged exposure to heat can also alter its color.
Tanzanite: Ranging from 6 to 7 on the Mohs scale of hardness. It is resistant to normal heat, light, and common chemicals, but can crack under very high temperatures or sudden changes. It is susceptible to attack by hydrochloric and hydrofluoric acids. Notably, tanzanite often begins as brownish zoisite and is heat-treated to achieve its characteristic blue to violet hues, a process that results in a permanent color change without compromising durability. Tanzanite is known for its pleochroism, displaying a color change when viewed in different lighting conditions – more violet in incandescent light and more blue in daylight. Rare examples exhibit a near-complete color change from amethyst purple to sapphire blue. The average tanzanite possesses higher clarity than many other popular gems, including sapphire, emerald, ruby, alexandrite, garnet, peridot, quartz, amethyst, citrine, ametrine, spinel, tourmaline, and zircon.
The following table summarizes the Mohs hardness scale comparison:
| Gemstone | Mohs Hardness |
|---|---|
| Turquoise | Not Specified |
| Zircon | 6 - 7.5 |
| Tanzanite | 6 - 7 |
Symbolism and Metaphysical Beliefs
Turquoise has a rich history of symbolism, associated with protection, health, and good fortune in ancient cultures. It was believed to ward off falls and warn of impending danger. Hindu traditions linked it to wealth.
While the provided sources do not detail specific metaphysical beliefs associated with zircon, its historical use suggests it was valued for its beauty and durability.
Tanzanite, being a more recent discovery, has less established traditional symbolism. However, its unique color, reminiscent of both sapphire and amethyst, has led to associations with the qualities of both stones. Its color is often likened to the eyes of Elizabeth Taylor, adding to its allure.
Care and Cleaning
Zircon requires careful handling due to its tendency to abrade. It is best to avoid wearing it during rough activities. Cleaning should be done with a soft brush and mild soap in warm water; ultrasonic and steam cleaners are not recommended.
Tanzanite, while resistant to many common factors, can crack under extreme temperatures or sudden changes. It should be cleaned with warm, soapy water, and ultrasonic and steam cleaners should be avoided.
The provided materials do not offer specific care instructions for turquoise.
Market Value and Investment Potential
The provided sources mention that tanzanite is becoming increasingly accepted as a December birthstone alongside blue zircon. It also suggests that tanzanite’s limited supply – potentially mined out within 15-30 years – could make it a worthwhile investment. However, this claim is qualified by the observation that mining companies may overestimate the remaining lifespan of the resource to attract investors. The sources do not provide any information on the market value of turquoise or zircon.
Conclusion
December’s birthstones – turquoise, zircon, and tanzanite – each offer a unique blend of history, beauty, and geological intrigue. Turquoise, with its ancient roots and protective symbolism, represents a connection to the past. Zircon, with its varied colors and durability, provides a classic gemological choice. Tanzanite, the newcomer, captivates with its rare origin, striking color change, and potential investment value. The choice among these three gems ultimately depends on individual preference, style, and appreciation for the diverse world of colored stones.