The twelfth month of the year is uniquely associated with a diverse palette of gemstones, offering a spectrum of cool, serene colors that mirror the winter season. Unlike most months, which are traditionally linked to a single gem, December is celebrated for its quartet of birthstones: Turquoise, Tanzanite, Blue Topaz, and Zircon. This multiplicity provides individuals born in December with a wide range of choices in terms of color, durability, symbolism, and price. The traditional stones, Turquoise and Zircon, have ancient roots, while Tanzanite and Blue Topaz have gained prominence as modern alternatives, each bringing its own distinct character to the birthstone lineage. This article delves into the history, geological origins, gemological properties, and cultural significance of each of these December birthstones, offering a comprehensive guide for gemstone enthusiasts, jewelry buyers, and students of gemology.
History and Lore: A Journey Through Time
The association of specific gemstones with particular months has evolved over millennia, with roots in ancient civilizations. The concept of birthstones can be traced back to ancient Egypt, Greece, and Rome, where gemstones were believed to possess mystical and healing properties. For December, this historical tapestry is woven with several distinct threads.
Turquoise stands as the oldest and most traditional December birthstone. It has been cherished for millennia, adorned by the pharaohs and rulers of ancient Egypt. Chinese artisans were carving turquoise more than 3,000 years ago. Its significance extended across cultures; in the 13th century, it was believed to protect the wearer from falls, particularly from horses, and would shatter as a warning of impending disaster. Hindu mystics held that seeing a turquoise after the new moon ensured fantastic wealth. For Native Americans, particularly the Apache, turquoise held a sacred place; they believed it could be found by following a rainbow to its end. The stone is deeply embedded in the spiritual life of many cultures, viewed as a sacred stone that embodies protection, truth, and calmness. Its name is thought to derive from the French "pierre turquoise," meaning "Turkish stone," due to its trade route through Turkey.
Zircon, the other traditional December birthstone, also boasts an ancient pedigree. The word "topaz" is believed to originate from the Sanskrit "tapas," meaning fire, and historically, topaz (often confused with zircon in ancient texts) was associated with strength and protection. Zircon itself is one of the oldest minerals on Earth, with deposits found in Australia dating back over 4.4 billion years. While the specific lore for blue zircon is less documented in the provided sources compared to turquoise, its enduring presence as a traditional birthstone underscores its historical importance.
The modern additions to December's birthstone list reflect evolving tastes and discoveries. Tanzanite, a relatively recent discovery, was first found in Tanzania in the 1960s. Its rapid rise to prominence as a birthstone is linked to its unique violet-blue hue and the marketing efforts of major gemological organizations. Blue Topaz, while topaz itself has ancient origins, the vibrant blue variety most commonly associated with December is a product of modern gemology. Naturally occurring blue topaz is exceptionally rare; the vast majority of blue topaz on the market today is created by irradiating and heat-treating colorless topaz. This process, developed in the latter half of the 20th century, made large, intensely blue stones readily available, leading to its popularity as an affordable and attractive modern birthstone option.
Geological Formation and Sources
Understanding where these gemstones originate adds depth to their appreciation. Each stone forms under distinct geological conditions, leading to unique characteristics and limited geographic sources.
Turquoise is a secondary mineral that forms in arid regions where acidic, copper-rich groundwater percolates through rocks containing aluminum and phosphorus. Over geological time, these solutions precipitate into veins and nodules. Major sources mentioned include Iran, the United States (particularly Arizona and New Mexico), Tibet, and India. Iranian turquoise, especially from the Nishapur region, is renowned for its consistent sky-blue color, while American turquoise often exhibits a greener hue and distinctive matrix (the remnants of the host rock).
Zircon is a primary mineral found in igneous and metamorphic rocks. It forms as crystals during the cooling of magma and is also present in many sandstone deposits. The sources for blue zircon are not explicitly detailed in the provided materials, but zircon mining occurs in various locations worldwide, including Australia, Cambodia, and Sri Lanka. The blue color in zircon used for gemstones is typically achieved through heat treatment of brown zircon crystals.
Tanzanite has a singular geological origin, making it exceptionally rare. It is found only in a small area of the Merelani Hills in northern Tanzania. The stone forms under specific metamorphic conditions where heat and pressure altered the mineral zoisite, introducing vanadium which gives tanzanite its signature blue-violet color. This limited geographic source adds to its allure and value.
Blue Topaz originates from pegmatites and hydrothermal veins. While topaz crystals are found in several countries, including Brazil, Nigeria, and Sri Lanka, the specific sources for the material used to create blue topaz are often these same locations. The colorless or pale topaz crystals are mined, then subjected to irradiation and heat treatment in controlled facilities to produce the desired blue shades. The United States, particularly Texas, Utah, and California, has deposits of topaz, with Texas even naming blue topaz its state gem.
Gemological Properties: The Science of the Stones
For gemologists and buyers, the physical and optical properties of a gemstone are paramount. These properties determine durability, appearance, and value.
Turquoise is a phosphate mineral (hydrated copper aluminum phosphate) with a Mohs hardness of 5 to 6, making it relatively soft and susceptible to scratching. It is typically semi-translucent to opaque, with colors ranging from sky blue to greenish-blue, often containing a brown or black matrix. Its refractive index is low, around 1.61 to 1.65, and it lacks the brilliance of many other gemstones due to its opacity.
Tanzanite is a variety of the mineral zoisite. It has a Mohs hardness of 6.5 to 7, making it more durable than turquoise but still requiring care in jewelry settings. Its most striking feature is its strong trichroism, displaying three different colors—blue, violet, and burgundy—depending on the crystal orientation. This property is carefully considered during cutting to maximize the desired blue-violet hue. Tanzanite is pleochroic and has a refractive index of approximately 1.69 to 1.70.
Blue Topaz, a variety of the mineral topaz, is significantly harder, with a Mohs hardness of 8. This makes it very resistant to scratching and suitable for all types of jewelry, including rings. It is typically transparent and has a vitreous luster. The color in blue topaz is entirely due to treatment; natural blue topaz is extremely rare. The treated stones exhibit a range of blues, from pale sky blue to deep "London Blue." Topaz has a refractive index of about 1.63 to 1.64.
Zircon (not to be confused with the synthetic cubic zirconia) is one of the hardest natural gemstones, with a Mohs hardness of 7.5. It is also brittle due to its perfect cleavage in two directions, which requires careful cutting and setting to avoid chipping. Blue zircon, typically heat-treated from brown zircon, is known for its high brilliance and fire, often compared to diamond. It has a high refractive index of about 1.92 to 1.98, contributing to its sparkle.
The following table summarizes key gemological properties based on the provided sources:
| Gemstone | Mineral Group | Mohs Hardness | Typical Colors | Key Optical Property |
|---|---|---|---|---|
| Turquoise | Phosphate | 5 - 6 | Sky blue, greenish-blue | Opaque, often with matrix |
| Tanzanite | Zoisite | 6.5 - 7 | Blue-violet, violet-blue | Strong trichroism |
| Blue Topaz | Topaz | 8 | Pale blue to deep blue | Transparent, vitreous luster |
| Zircon | Zircon | 7.5 | Icy pale blue, vibrant blue | High brilliance and fire |
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, gemstones carry layers of meaning and symbolism, often tied to their historical lore and perceived energies.
Turquoise is universally associated with protection, truth, and calmness. Its traditional significance includes friendship, good fortune, and healing. Different cultures attribute specific powers to it: it was thought to ensure health, protect against falls, and bring wealth. For Sagittarius, it supports truth-seeking, while for Capricorn, it aids in emotional balance.
Tanzanite is linked to ambition, clarity, and emotional healing. Its modern symbolism often connects it to transformation and higher consciousness. As a stone of the 20th century, it is sometimes associated with visionary insight and calmness, helping to focus the mind. It is particularly suited for Capricorn, supporting focus and clarity.
Blue Topaz symbolizes calmness, love, and clarity. Its serene blue color evokes peace and tranquility. Historically, topaz was associated with strength and protection. In modern times, blue topaz is known for representing love and fidelity, making it a popular choice for romantic gifts. It is believed to promote clear communication and emotional stability.
Zircon has historical associations with strength and protection, stemming from its ancient connection to the word "tapas" (fire). While specific metaphysical beliefs for blue zircon are less detailed in the sources, its brilliance and durability lend themselves to symbolism of resilience and clarity. As a traditional birthstone, it carries the weight of ancient beliefs in its protective qualities.
The choice of a December birthstone can therefore be guided not only by color and durability but also by the symbolic meaning that resonates most with the individual.
Care and Cleaning
The longevity of gemstone jewelry depends heavily on proper care, which is directly tied to each stone's physical properties.
Turquoise, with its low hardness (5-6) and porous nature, is the most delicate of the December stones. It should be protected from chemicals, perfumes, and prolonged exposure to water or sunlight, which can cause discoloration. Cleaning should be done with a soft, dry cloth; avoid ultrasonic cleaners and steam. Store it separately to prevent scratching.
Tanzanite (hardness 6.5-7) requires careful handling due to its perfect cleavage. It is susceptible to chipping if struck hard. It is safe to clean with warm, soapy water and a soft brush. Avoid sudden temperature changes and ultrasonic cleaners, which can cause internal fractures.
Blue Topaz (hardness 8) is the most durable of the four and is relatively easy to care for. It can be cleaned with warm, soapy water and a soft brush. It is resistant to most chemicals and heat, making it suitable for everyday wear. However, like all gemstones, it should be protected from hard blows.
Zircon (hardness 7.5) is also quite durable but has perfect cleavage, making it vulnerable to chipping. It should be handled with care and stored in a padded jewelry box. Cleaning with warm, soapy water and a soft brush is safe. Avoid ultrasonic cleaners and extreme temperature changes, as zircon can be sensitive to heat.
For all December birthstones, removing jewelry during physical activities, household chores, and when applying cosmetics will help preserve their beauty and integrity.
Conclusion
December's birthstones offer a remarkable range of choices, each with its own story, scientific makeup, and symbolic meaning. From the ancient, protective Turquoise to the rare, violet-blue Tanzanite, the durable and serene Blue Topaz, and the brilliant, traditional Zircon, there is a gem to suit every preference and personality. Understanding their histories, from the tombs of Egyptian pharaohs to the mines of Tanzania, enriches their value. Their gemological properties—from the soft, matrix-veined turquoise to the fiery brilliance of zircon—guide their use and care in jewelry. Ultimately, whether chosen for its color, durability, symbolism, or personal significance, each December birthstone carries the cool, serene essence of its month, making it a meaningful and cherished adornment for those born in the twelfth month of the year.