December is uniquely represented by not one, but two birthstones: Zircon and Tanzanite. Both gems offer a vibrant spectrum of color and possess a fascinating history, making them highly sought-after in the world of jewelry. While Zircon has a longer tradition as a December birthstone, Tanzanite, discovered more recently, has quickly gained prominence thanks to successful marketing and its exceptional beauty. This article will delve into the history, geological origins, gemological properties, and symbolism of these two captivating gemstones.
A History of December’s Stones
The tradition of associating specific gemstones with birth months dates back thousands of years. Early examples of this practice can be found in biblical texts, such as the Book of Exodus, which references twelve stones. However, the standardization of birthstone lists is a more recent development. Zircon has long been recognized as a December birthstone, while Tanzanite was officially added in 2002. The introduction of Tanzanite was largely driven by Tiffany & Co., who recognized its international appeal and launched a significant advertising campaign to promote it in 1968, shortly after its discovery.
Geological Formation and Sources
Zircon is found in a variety of colors, including red, orange, brown, yellow, green, and blue. Primary sources of Zircon production are Sri Lanka and Australia. Its formation occurs in metamorphic rocks, and it can be found in alluvial deposits.
Tanzanite, on the other hand, is exclusively mined in the Merelani Hills of Tanzania, making it a geographically unique gemstone. Its discovery in Tanzania led to its naming, and it remains the only place on Earth where commercial quantities of this gem are found.
Gemological Properties: Zircon
Zircon possesses a hardness ranging from six to seven and a half on the Mohs scale. This means that while it can be used in everyday jewelry, it requires careful handling to avoid scratches and damage. It is commonly heat-treated to enhance or alter its color, producing a wider range of hues.
The gemological properties of Zircon are as follows:
- Hardness: 6 - 7.5 (Mohs scale)
- Color: Red, orange, brown, yellow, green, blue
- Sources: Sri Lanka, Australia
- Treatment: Commonly heat-treated
Gemological Properties: Tanzanite
Tanzanite is also rated at a six to a seven on the Mohs scale, indicating a similar level of durability to Zircon. It is known for its high clarity and vivid colors, making it a particularly attractive gemstone. Tanzanite is resistant to heat, light, and common chemicals.
The gemological properties of Tanzanite are as follows:
- Hardness: 6 - 7 (Mohs scale)
- Color: Vivid blues and violets
- Source: Merelani Hills, Tanzania
- Treatment: Not explicitly mentioned in the sources.
Symbolism and Metaphysical Beliefs
Garnet, the January birthstone, is believed to represent fertility and rebirth, offering wisdom and new opportunities to those born in that month. It is also thought to dispel negative emotions like self-doubt and depression, fostering confidence and emotional strength.
Zircon, while not extensively detailed in the provided sources regarding symbolism, is noted for its brilliance.
Tanzanite is associated with international appeal, a testament to the successful marketing campaign launched by Tiffany & Co. It is also commonly gifted to celebrate a 24th wedding anniversary.
Bloodstone, another December birthstone, has a rich history of metaphysical beliefs. Historically, it was believed to provide health, youth, strength, and even invisibility. More recently, it has been regarded as a lucky charm. Its name originates from a religious belief linking its red spots to the blood of Christ.
Care and Cleaning
Due to their similar hardness levels (6-7.5 on the Mohs scale), both Zircon and Tanzanite require careful handling and cleaning. Zircon, if treated correctly, can be used in everyday jewelry. Tanzanite is best suited for earrings or pendants, as these settings are less prone to impact and abrasion. Bloodstone should be protected from hot temperatures and stored in a soft fabric to prevent scratches. Opal, with a hardness of only 5-6.5, requires particularly gentle cleaning with soapy water to avoid damage.
Additional December Birthstones
Beyond Zircon and Tanzanite, several other gemstones are associated with December. Turquoise, known for its shifting colors and symbolic representation of truth, purity, and hope, is often gifted for 14th wedding anniversaries. It is sourced primarily from Australia, Mexico, Brazil, and Ethiopia, but deposits exist in many other countries.
Diamonds, the most famous gemstone, are also linked to December. Their name, derived from the Greek word "Adamas" meaning "unbreakable," reflects their exceptional hardness and durability. Diamonds have long been associated with healing powers, beauty, happiness, strength, and longevity, and are a traditional choice for engagement rings and wedding anniversary gifts.
Other Notable Birthstones
The provided sources also offer glimpses into the properties and origins of other birthstones:
- Ruby: Sourced from Vietnam, Mozambique, Pakistan, Sri Lanka, and Madagascar, Rubies are rated nine in hardness, just below diamonds. They are often heat-treated to improve their color.
- Peridot: Traditionally used as a protective talisman, Peridot ranges in color from greenish-yellow to yellowish-green and is gifted for 16th wedding anniversaries.
- Spinel: Available in a wide range of colors, including purple, orange, blue, green, pink, and red, Spinel was believed to cure blood loss and promote harmony. It is gifted for 22nd wedding anniversaries.
- Opal: Known for its "play-of-color," Opal is seen as a symbol of truth, purity, and hope and is gifted for 14th wedding anniversaries.
- Tourmaline: Believed to inspire art, Tourmaline comes in multiple colors and is gifted for eighth wedding anniversaries.
- Topaz: Associated with beauty, intelligence, and longevity, Topaz is available in various colors and is gifted for fourth and 23rd wedding anniversaries.
A Table of December Birthstones and Their Properties
| Gemstone | Hardness (Mohs) | Color(s) | Source(s) |
|---|---|---|---|
| Zircon | 6 - 7.5 | Red, Orange, Brown, Yellow, Green, Blue | Sri Lanka, Australia |
| Tanzanite | 6 - 7 | Vivid Blues and Violets | Merelani Hills, Tanzania |
| Bloodstone | 6.5 - 7 | Opaque Green with Red Spots | India, U.S., Australia, China, Brazil |
| Diamond | 10 | Colorless, Yellow, Brown, etc. | Various |
| Turquoise | 5 - 6 | Blue-Green | Australia, Mexico, Brazil, Ethiopia |
Conclusion
December’s birthstones, Zircon and Tanzanite, represent a captivating blend of tradition and modern discovery. Zircon, with its long history and diverse color palette, offers a classic choice, while Tanzanite, with its unique origin and vibrant hues, provides a more contemporary option. Alongside other December-associated gems like Bloodstone, Turquoise, and Diamond, these stones offer a wealth of choices for those seeking a meaningful and beautiful connection to their birth month. The enduring appeal of these gemstones lies not only in their aesthetic qualities but also in the rich history, symbolism, and geological wonders they represent.