December is unique among the months, possessing not one, but two recognized birthstones: Zircon and Tanzanite. Both gems offer a vibrant spectrum of color and a fascinating history, though their origins and cultural significance differ considerably. This article will explore the geological properties, historical context, and symbolism of these December birthstones, drawing solely from available sources.
History and Lore
The tradition of associating specific gemstones with birth months has ancient roots, though the modern list evolved over time. While the sources do not detail the earliest origins of birthstone associations, they highlight the relatively recent addition of Tanzanite to the December roster. Tanzanite was officially recognized as a December birthstone in 2002, largely due to a successful marketing campaign launched by Tiffany & Co. in 1968. The company recognized the gem’s international appeal and actively promoted it, naming it “Tanzanite” after its place of discovery in Tanzania.
Zircon, conversely, has a longer, though less documented, history as a December birthstone. Sources indicate its use in jewelry dates back centuries, with the gem being valued for its brilliance and availability in a wide range of colors. The sources do not provide specific details on ancient beliefs surrounding Zircon, but mention its hardness makes it suitable for everyday wear when properly treated.
Geological Formation and Sources
Zircon’s origins are geographically diverse. Primary sources of production are located in Sri Lanka and Australia. The sources do not detail the specific geological processes involved in Zircon formation, but its hardness – ranging from six to seven and a half on the Mohs scale – suggests a robust crystalline structure. It is also commonly heat-treated to enhance or alter its color, indicating a responsiveness to thermal processes.
Tanzanite, in contrast, is remarkably localized in its origin. The only place on Earth where Tanzanite is commercially mined is the Merelani Hills in Tanzania. This singular source contributes to its relative rarity and value. The sources do not detail the specific geological conditions necessary for Tanzanite formation, but its hardness of six to seven suggests a similar level of durability to Zircon.
Gemological Properties
Both Zircon and Tanzanite exhibit properties that make them desirable gemstones, though they differ in key characteristics. Zircon is noted for its wide color range, encompassing red, orange, brown, yellow, green, and blue hues. Its hardness falls within the range of 6 to 7.5 on the Mohs scale, making it susceptible to scratching with prolonged wear, but suitable for jewelry with appropriate care.
Tanzanite is celebrated for its high clarity and vivid colors. The sources specifically mention its deep blues, exuding a luxurious appearance. It also possesses a hardness of 6 to 7 on the Mohs scale, similar to Zircon. Both gems are resistant to heat, light, and common chemicals, though the sources recommend using Tanzanite primarily in earrings or pendants due to its relative softness.
A comparison of hardness is shown below:
| Gemstone | Mohs Hardness |
|---|---|
| Zircon | 6 - 7.5 |
| Tanzanite | 6 - 7 |
| Diamond | 10 |
Symbolism and Metaphysical Beliefs
The sources offer limited insight into the specific symbolism associated with Zircon and Tanzanite beyond their general association with positive and pure things. However, the sources do mention that birthstones are believed to bestow exceeding fortunes and strengthened fortitude upon those born in their corresponding month.
Other gems mentioned in the sources have associated symbolism. Peridot, for example, was historically used as a protective talisman. Spinel was believed to cure blood loss and inflammatory diseases and promote harmony. Sapphires, particularly the Star Sapphire, are valued for their unique asterism (star-like pattern) and the depth of their color. Opal, with its varied colors, was historically considered good luck, believed to contain a little of all other gemstones, though this belief is reversed in some modern Russian cultures.
Care and Cleaning
Given their similar hardness levels, Zircon and Tanzanite require similar care. The sources recommend treating Zircon correctly to ensure its longevity in jewelry. While both are resistant to heat, light, and common chemicals, their relative softness necessitates careful handling to avoid scratches. Regular cleaning with mild soap and water is advisable to maintain their brilliance.
Additional Birthstones and Zodiac Associations
The sources expand beyond December birthstones to provide a broader overview of birthstones by month and zodiac sign. The table below summarizes birthstones by month:
| Month | Birthstone | Color |
|---|---|---|
| August | Citrine | Yellow |
| September | Sapphire | Dark Blue |
| October | Opal | Varied |
| November | Carnelian | Deep Red |
| January | Garnet | Deep Red |
| March | Aquamarine | Marine Fluorescence |
The sources also detail a tradition of selecting gemstones based on the day of the week, linking each day to a specific stone and its associated planetary energy. Furthermore, the concept of zodiac birthstones is introduced, differentiating them from standard birthstones by often utilizing semi-precious gems linked to astrological signs.
Other Gemstone Information
The sources provide brief details on a variety of other gemstones, including Ruby (hardness of 9, next to diamond), Peridot (derived from the Arabic word 'faridat' meaning 'gem'), Spinel (named after the Latin word 'spina' meaning 'thorn'), and Topaz. These gems are sourced from various locations worldwide, including the U.S., Pakistan, Vietnam, Tanzania, Myanmar, China, Sri Lanka, and Madagascar.
Conclusion
Zircon and Tanzanite represent the vibrant duality of December’s birthstones. While Zircon boasts a long-standing, though less documented, history, Tanzanite’s relatively recent discovery and successful marketing have established it as a highly sought-after gem. Both stones offer a captivating array of colors and a moderate level of durability, making them suitable for a variety of jewelry applications. The tradition of associating gemstones with birth months continues to resonate, offering a personal and symbolic connection to these beautiful creations of nature.