December is uniquely blessed with a trio of captivating blue birthstones: tanzanite, turquoise, and zircon. While a single December birthstone is often sought, the tradition allows for a spectrum of blues, ranging from the vibrant violet-blue of tanzanite to the intense blue-green of turquoise and the rainbow hues of zircon. These gemstones each possess a rich history, distinct geological origins, and unique symbolic meanings, making December a particularly colorful month for gemstone enthusiasts.
History and Lore
Turquoise boasts the longest history of the three December birthstones, with evidence of its use dating back to 6000 B.C. in ancient Egypt. Pharaohs and rulers adorned themselves with this stone, believing it to possess protective powers. Chinese artisans were also carving turquoise over 3,000 years ago. The name “turquoise” itself has debated origins, stemming either from the French phrase “pierre turquoise” meaning “Turkish stone,” or the Persian word “fiouze” for the color turquoise. Historically, turquoise was believed to guarantee health and good fortune, and from the 13th century onward, it was thought to safeguard wearers from falls, even breaking into pieces to warn of impending disaster. Hindu mystics believed viewing turquoise after a new moon would bring wealth. Significant sources for high-quality turquoise are found in Iran, though notable specimens also originate from New Mexico and Arizona in the United States, as well as Afghanistan and Australia.
Sapphire, while most commonly associated with September, also appears as a blue gemstone option. Its value is determined by the depth of its color, carat weight, and the presence of asterism – a star-like pattern. Sapphires can be heat-treated to enhance color and clarity.
Blue zircon is another December birthstone, offering a range of colors. The sources indicate that zircon can exhibit a rainbow of hues.
Tanzanite is the newest addition to the December birthstone family, discovered relatively recently. The sources do not provide a specific date for its discovery.
Geological Formation and Sources
The formation of these blue gemstones varies significantly. Turquoise is a semi-translucent to opaque gem formed with veins of matrix – remnants of the rock in which it originated. Zircon, known for its rainbow varieties, is formed under specific geological conditions that allow for a range of colors. Tanzanite’s origins are not detailed in the provided sources beyond its inclusion as a December birthstone.
Aquamarine, a March birthstone, is commonly mined in Russia and the United States, but can be found globally. It is a transparent gem with a slight blue tint, and can also appear in white, yellow, pink, and light green shades.
Shattuckite, a less common blue gemstone, derives its color from the presence of copper and often displays patterning like mottling or webbing. It is typically a collector’s stone due to its relative softness and susceptibility to damage.
Sillimanite and Scorodite are also mentioned as blue gemstones, but are not typically used in jewelry due to toxicity (Scorodite contains arsenic) or fragility (Shattuckite).
Gemological Properties
The provided sources offer limited detailed gemological data, but some properties are noted. Turquoise ranges from blue to green and is semi-translucent to opaque. Aquamarine has a Mohs hardness of 8. Blue topaz, featured in jewelry collections, is also mentioned.
Sapphire, a September birthstone, gets its blue coloring from the presence of titanium and iron. It can undergo heat treatments to enhance color and clarity.
Zircon exhibits a range of colors, including blue, and can be synthetically produced.
The sources do not provide chemical formulas, refractive indices, or specific gravity data for these gemstones.
Here's a table summarizing the limited gemological data available:
| Gemstone | Color(s) | Hardness (Mohs) | Transparency |
|---|---|---|---|
| Turquoise | Blue to Green | Not specified | Semi-translucent to Opaque |
| Aquamarine | Blue, White, Yellow, Pink, Green | 8 | Transparent |
| Sapphire | Blue | Not specified | Not specified |
| Zircon | Rainbow Hues | Not specified | Not specified |
Symbolism and Metaphysical Beliefs
Throughout history, these blue gemstones have been imbued with symbolic meaning. Turquoise, as previously mentioned, was believed to offer protection, health, and good fortune. Ancient Egyptians associated it with royalty and protection, while Hindus linked it to wealth.
The sources mention that ancient and medieval astrologers assigned gemstones to planets, believing them to reflect the stars and connect individuals to constellations. Originally, zodiac stones and birthstones were the same, but today, zodiac birthstones are often semi-precious, while standard birthstones can include precious gems. The provided zodiac chart lists birthstones by sign, but does not detail specific metaphysical beliefs associated with each stone.
Care and Cleaning
The sources do not provide detailed care and cleaning instructions for these gemstones. However, given the varying hardness levels, it can be inferred that softer stones like turquoise and shattuckite require more careful handling and cleaning than harder stones like sapphire and aquamarine. It is generally advisable to avoid harsh chemicals and ultrasonic cleaners when cleaning gemstones, and to use a soft cloth and mild soap and water.
Additional Blue Gemstones
Beyond the traditional birthstones, several other blue gemstones are mentioned. Blue sapphire is a popular choice for faceted gemstones and engagement rings. Apatite is noted as a bright blue gemstone. Shattuckite, while often a collector’s item, can appear in jewelry but requires careful handling. Scorodite, though attractive, is rarely used in jewelry due to its arsenic content. Sillimanite is also mentioned. Blue pearls, available in Akoya, South Sea, and Tahitian varieties, offer a range of blue hues, from light to dark.
Conclusion
December’s birthstones – tanzanite, turquoise, and zircon – offer a diverse palette of blue hues, each with a unique history and symbolic significance. From the ancient protective powers attributed to turquoise to the more recent discovery of tanzanite, these gemstones represent a rich tapestry of geological formation, cultural lore, and enduring beauty. While the provided sources offer a glimpse into the world of these blue gems, further research is encouraged to fully appreciate their intricate properties and captivating allure.