December is unique among the months, boasting not one, but four recognized birthstones: Tanzanite, Turquoise, Blue Zircon, and Blue Topaz. All four gemstones share a common thread – a beautiful range of blue hues – but each possesses distinct geological origins, historical significance, and gemological properties. This article will delve into the characteristics of each of these December birthstones, exploring their history, sources, properties, and symbolism, as understood through available gemological and historical data.
A Quartet of December Gems
The tradition of associating specific gemstones with each month evolved over time. While Blue Zircon historically held prominence as the primary December birthstone, the inclusion of Turquoise, Blue Topaz, and, more recently, Tanzanite, offers a wider spectrum of choice and meaning for those born in the final month of the year. The prevalence of blue across these stones reflects the cool tones of the winter season.
Turquoise: A Stone of Ancient Protection
Turquoise, a semi-translucent to opaque gem, ranges in color from blue to green, often displaying veins of matrix – remnants of the host rock in which it formed – running through it. This December birthstone has a rich history, cherished for millennia across numerous cultures. Ancient Egyptians adorned themselves with turquoise, and Chinese artisans were carving it over 3,000 years ago.
Historically, turquoise was believed to possess protective powers. From the 13th century onward, it was thought to safeguard wearers from falls, particularly from horseback, and to warn of impending disaster by fracturing. In Hindu mysticism, viewing turquoise after beholding the new moon was believed to ensure great wealth. The quality of turquoise is graded based on its color, matrix, and texture, with dense textures exhibiting better polish luster than coarser ones. The most valuable turquoise displays a bright “robin’s egg” or “sky” blue color with even distribution and no undertones, though medium-dark tones are also prized for their vibrancy.
Blue Zircon: A Brilliant, Ancient Gem
Blue Zircon, while often confused with cubic zirconia, is a natural gemstone mined primarily in Thailand, Cambodia, and Vietnam. Natural zircon occurs in a variety of colors, and some material is heat-treated to achieve a pastel blue hue. Zircon is notable for its high refractive index, contributing to its brilliance, and was historically used as a diamond substitute.
Interestingly, zircon contains trace amounts of uranium and thorium, making it valuable in radiometric dating. Some zircon specimens have been calculated to be up to 4.4 billion years old, representing the oldest minerals recorded on Earth. While large zircon specimens are occasionally found, most gems on the market are relatively small. Large, high-quality blue zircons can be quite expensive, leading to Blue Topaz as a popular and more affordable alternative. Zircon exhibits a range of colors, including blue (often with greenish undertones), green (typically brownish), yellow to orange (“jargon” or “melichrysos”), red (“hyacinth/jacinth”), purple, and even colorless. Radioactive decay within zircons can alter their crystalline structure and color over time, with “high zircon” specimens generally being more stable and displaying blue, colorless, or brownish-orange hues.
Tanzanite: A Modern Discovery
Tanzanite is a relatively recent addition to the birthstone family, discovered in the 1960s near Mount Kilimanjaro. It was first marketed by Tiffany & Co., and quickly gained popularity for its stunning blue and violet hues. Tanzanite is a transparent blue crystal that can be faceted into various shapes, displaying colors ranging from blue to purple, rivaling the finest sapphires in intensity.
A key characteristic of Tanzanite is its strong pleochroism, meaning it exhibits different colors when viewed from different angles and under different lighting conditions. Like Blue Zircon, Tanzanite is commonly heat-treated to enhance its coloration. Uniquely, Tanzanite is found in a limited geographical area around Mount Kilimanjaro and is not known to exist anywhere else in the world.
Blue Topaz: An Affordable Alternative
Blue Topaz serves as a readily available and affordable alternative to other December birthstones. It closely resembles Blue Zircon in appearance, offering a similar aesthetic at a more accessible price point. While not detailed in the provided sources, it is understood that Topaz is a silicate mineral known for its hardness and clarity.
Gemstone Quality and Grading
Evaluating the quality of these December birthstones involves considering several factors: color, cut, clarity, carat weight, and treatments. Turquoise is uniquely graded on its color, matrix, and texture. Tanzanite is valued for its vibrant blue and purplish-blue hues, with strong pleochroism enhancing its value. Zircon’s price is influenced by its color, with blue being the most popular and vivid greens and reds being more valuable.
For Turquoise, cabochons, inlays, carvings, and beads are common cuts. Tanzanite and Blue Zircon are typically faceted to maximize their brilliance. The grading of color is specific to each stone: Turquoise values bright sky blue, Tanzanite favors vibrant pure blue, and Zircon prizes vivid blue hues.
Symbolism and Cultural Significance
Throughout history, birthstones have been associated with specific meanings and powers. Turquoise was believed to guarantee health and good fortune, while Blue Zircon, due to its brilliance, may have been associated with clarity and wisdom. Tanzanite, as a more modern discovery, has yet to accumulate the same depth of historical symbolism, but its rarity and beauty contribute to its perceived value and significance. The tradition of wearing birthstones, particularly in India, involves setting the stone in jewelry to maintain direct contact with the skin, believed to channel the stone’s benefits to the wearer.
December Birthstone by Date
The provided sources indicate a variation in birthstone assignment by date within December:
- December 4th: Blue Topaz
- December 5th: Tanzanite
- December 6th: Turquoise
- December 7th: Blue Zircon
- December 8th: Blue Topaz
- December 9th: Tanzanite
- December 10th: Turquoise
- December 11th: Blue Zircon
- December 12th: Blue Topaz
- December 13th: Tanzanite
- December 14th: Turquoise
- December 15th: Blue Zircon
- December 16th: Blue Topaz
- December 17th: Tanzanite
- December 18th: Turquoise
- December 19th: Blue Zircon
- December 20th: Blue Topaz
- December 21st: Tanzanite
- December 22nd: Turquoise
- December 23rd: Blue Zircon
- December 24th: Blue Topaz
- December 25th: Tanzanite
- December 26th: Turquoise
- December 27th: Blue Zircon
- December 28th: Blue Topaz
- December 29th: Tanzanite
- December 30th: Turquoise
- December 31st: Blue Zircon
Conclusion
December’s birthstones – Tanzanite, Turquoise, Blue Zircon, and Blue Topaz – offer a captivating array of blue hues and rich histories. From the ancient protective powers attributed to Turquoise to the modern allure of Tanzanite and the enduring brilliance of Blue Zircon, each gemstone holds a unique place in the world of gemology and cultural lore. The availability of Blue Topaz provides an accessible option for those seeking the beauty of a December birthstone. Ultimately, the choice of which stone to embrace is a personal one, reflecting individual preferences and a connection to the symbolism and history of these remarkable gems.