December is uniquely adorned in the gemological calendar, holding not one, but four distinct birthstones. This abundance reflects a cool, wintry palette ranging from icy blues to deep violets, mirroring the season’s skies and twilight. The four gemstones—Turquoise, Zircon, Tanzanite, and Blue Topaz—each possess a unique history, geological origin, and set of properties that appeal to a wide range of preferences. While Turquoise is the oldest and most traditional, the inclusion of Zircon, Tanzanite, and Blue Topaz offers modern choices in terms of color, durability, and price. This article delves into the geological formation, gemological properties, historical lore, and cultural significance of each of December’s birthstones, providing a comprehensive guide for enthusiasts, collectors, and those seeking a meaningful gemstone connection.
History and Lore: A Journey Through Time and Tradition
The history of December’s birthstones is a tapestry woven from ancient civilizations, modern discoveries, and evolving commercial practices. The journey began with Turquoise, one of the oldest known gemstones in human history.
Turquoise: The Ancient Protector Turquoise has been cherished for millennia, with its use dating back over 3,000 years. Chinese artisans carved it more than three millennia ago, and it was a favored adornment for the pharaohs and rulers of ancient Egypt. Its historical significance extends beyond mere decoration; it was imbued with protective powers. From the 13th century onward, it was believed to safeguard the wearer from falls, particularly from horses, and was thought to break into several pieces as a warning of impending disaster. Hindu mystics maintained a belief that seeing a turquoise after beholding the new moon would ensure fantastic wealth. In the Americas, the Apache believed that following a rainbow to its end would reveal turquoise. This stone is not only a birthstone but also a sacred stone in many cultures, symbolizing friendship, protection, and good fortune.
Zircon: The Diamond Imposter with a Royal Past Zircon’s history is often overshadowed by its brilliance, which can be mistaken for diamond. While its specific discovery date is not pinpointed in the provided materials, it has been used in jewelry for centuries. Its inclusion into the official birthstone list is a more modern development. In 1952, the Jewelry Industry Council of America updated the standardized list of birthstones, adding Zircon to December’s offerings. This addition provided a traditional gemstone with exceptional sparkle to complement the more opaque or softer stones of the month.
Tanzanite: A Modern Marvel Tanzanite is the newest addition to the December family. It was only discovered in the 20th century and was officially added to the birthstone list in 2002 by the Jewelry Industry Council of America. Its rarity and unique coloration made it an instant sensation. As a relatively new discovery in the gem world, it lacks the ancient lore of Turquoise but carries modern symbolism linked to transformation, new beginnings, and clarity. It represents a shift in the gemstone market, where a single-source gemstone can achieve global recognition and value in a short period.
Blue Topaz and Standardization The exact historical origin of Blue Topaz is unknown, as it has been found throughout history. However, its official recognition as a birthstone is tied to the standardization of birthstones in the 20th century. In 1912, the National Association of Jewelers standardized the unofficial American birthstones, a list that has been updated over time. Blue Topaz, while not listed as an official December birthstone in the traditional sense in all sources, is frequently mentioned as a popular modern alternative or addition. Its popularity grew as it offered a durable, affordable, and vividly blue option. It is notably the official state gem of Texas.
The reason December has multiple birthstones is not definitively known, but sources suggest it was to offer more variety in color, style, and affordability. The evolution of the birthstone list, driven by consumer demand and commercial offerings, allowed for the inclusion of stones like Zircon (1952) and Tanzanite (2002), while Blue Topaz emerged as a popular modern alternative.
Geological Formation and Global Sources
Each of December’s birthstones forms under distinct geological conditions and is sourced from specific regions of the world, influencing their availability and value.
Turquoise: An Hydrated Phosphate Turquoise is a phosphate mineral that forms in arid regions where acidic, copper-rich groundwater reacts with minerals containing aluminum and phosphorus. It is a semi-translucent to opaque gem, ranging from sky blue to greenish hues, often containing veins of matrix—the remnants of the host rock. Major sources include Iran (historically the most prized), the United States (particularly the Southwest), Tibet, and India. The United States has a rich turquoise mining history, with deposits in states like Arizona, Nevada, and New Mexico. The stone’s color and matrix patterns are directly influenced by its specific geological formation environment.
Zircon: A Zirconium Silicate Zircon is a zirconium silicate mineral that forms in igneous and metamorphic rocks. It is one of the oldest minerals on Earth, with some crystals dating back billions of years. While Zircon is found globally, the gem-quality blue variety is less common. The provided sources do not specify the primary mining locations for blue zircon, but it is a durable mineral that can be found in various geological settings. Its formation typically occurs in high-temperature environments, such as in pegmatites or metamorphic rocks.
Tanzanite: A Single-Source Gemstone Tanzanite’s geological story is extraordinary. It is a variety of the mineral zoisite and is found in only one location on Earth: the Merelani Hills of northern Tanzania, near the base of Mount Kilimanjaro. This extreme rarity is a key factor in its high value and expense. Tanzanite forms through a unique geological process involving the metamorphism of the host rocks. Its limited geographic source makes it one of the rarest gemstones in the world, with supplies believed to be finite.
Blue Topaz: A Widespread Silicate Topaz is a silicate mineral of aluminum and fluorine. It crystallizes in pegmatites and vapor-rich cavities in igneous rocks like rhyolite. Naturally occurring blue topaz is rare; most blue topaz on the market is created by irradiating and heat-treating colorless or pale yellow topaz. Sources for topaz are widespread. For Blue Topaz specifically, sources mention it is mined in Sri Lanka, Brazil, Mexico, Nigeria, and the United States (including Texas, Utah, and California). Its relative abundance compared to Tanzanite makes it a more affordable and accessible blue gemstone.
Gemological Properties: A Scientific Profile
Understanding the physical and chemical properties of each stone is crucial for identification, valuation, and care. The following table summarizes the key gemological characteristics based on the provided sources.
| Gemstone | Mineral Family | Chemical Formula (General) | Mohs Hardness | Typical Color Range | Transparency | Notable Features |
|---|---|---|---|---|---|---|
| Turquoise | Phosphate | Hydrated copper aluminum phosphate | 5 – 6 | Sky blue to greenish-blue | Semi-translucent to opaque | Often contains matrix (host rock veins); color can fade with prolonged sunlight exposure. |
| Zircon | Zirconium Silicate | ZrSiO₄ | 6.5 – 7.5 | Bright, clear blue (treated); also colorless, brown, green | Transparent to translucent | High refractive index and strong dispersion ("fire"), often mistaken for diamond. Can be heat-treated to achieve blue color. |
| Tanzanite | Zoisite | Ca₂(Al, OH)₂(SiO₄) | 6 – 7 | Rich violet-blue, often pleochroic (shows blue and violet) | Transparent | Pleochroism is a key characteristic; its color can shift depending on the light and viewing angle. |
| Blue Topaz | Silicate | Al₂SiO₄(F,OH)₂ | 8 | Sky blue to deep London blue (treated) | Transparent | Naturally occurring blue is rare; most commercial blue topaz is irradiated and heat-treated colorless topaz. High durability. |
Color and Clarity Color is the most defining attribute of these December stones. Turquoise is prized for its unique, often veined, opaque color. Zircon’s blue is typically bright and clear, a result of treatment. Tanzanite offers a unique violet-blue hue with pleochroism, meaning it displays different colors from different angles. Blue Topaz ranges from pale sky blue to deep, saturated "London Blue."
Clarity varies significantly. Turquoise is almost always opaque or semi-translucent with inclusions (matrix). Zircon, Tanzanite, and Blue Topaz are generally transparent to translucent, with clarity grades affecting their value. Tanzanite is often found with some inclusions, which are accepted in the trade.
Durability and Wearability Durability is a critical factor for jewelry intended for daily wear. The Mohs hardness scale is a key indicator. * Blue Topaz is the most durable of the group, with a hardness of 8 on the Mohs scale, making it resistant to scratching and suitable for everyday jewelry like rings. * Zircon has a hardness of 6.5 to 7.5, making it fairly durable but more susceptible to chipping than topaz due to its brittleness. It is better suited for pendants or earrings than rings. * Tanzanite (hardness 6-7) and Turquoise (hardness 5-6) are the most fragile. Both are prone to scratching, breaking, and chipping. They are best set in protective settings and worn as occasional jewelry rather than daily-wear rings. Turquoise is also sensitive to chemicals, heat, and prolonged sunlight, which can cause discoloration.
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, each gemstone carries a legacy of symbolic meaning and metaphysical belief, often rooted in ancient lore and modern interpretations.
Turquoise: The Stone of Protection Turquoise is universally regarded as a talisman of protection, good fortune, and calm. It is believed to be a steadying force, offering grounding and a sense of tranquility. Its historical association with safeguarding travelers and warriors continues in modern metaphysical practices, where it is used to ward off negative energy and promote emotional balance.
Zircon: The Stone of Clarity Zircon is associated with enhancing mental clarity, wisdom, and spiritual growth. It is believed to help focus the mind, stimulate the wearer’s intellect, and promote a sense of order and balance. Its brilliant sparkle is often linked to the illumination of one’s path and the attainment of wisdom.
Tanzanite: The Stone of Transformation As a modern gemstone, Tanzanite’s symbolism is tied to its unique discovery and vibrant color. It is linked to transformation, new beginnings, and spiritual awakening. Its shifting violet-blue hues are seen as a metaphor for navigating change and gaining new perspectives. It is also associated with higher consciousness and intuition.
Blue Topaz: The Stone of Communication and Love Blue Topaz, particularly the deeper shades, is associated with love, fidelity, and clear communication. Its calming blue color is believed to soothe the mind, reduce stress, and encourage peaceful expression. In modern times, it is often given as a symbol of romantic love and commitment.
Care and Cleaning: Preserving Your Gemstone
Proper care is essential to maintain the beauty and longevity of these birthstones, and the methods vary significantly based on their physical properties.
Turquoise Care Due to its porosity and low hardness (5-6), turquoise requires gentle care. * Cleaning: Use only a soft, dry cloth. Avoid ultrasonic cleaners, steam cleaners, and chemical cleaners (including soaps and lotions), as they can damage the stone and its matrix. * Storage: Store separately to avoid scratches. Keep it away from prolonged direct sunlight, which can cause fading. * Wear: Remove turquoise jewelry before swimming, bathing, or engaging in physical activities to protect it from impacts and chemicals.
Zircon Care Zircon is brittle, meaning it can chip if struck, despite its moderate hardness. * Cleaning: Safe to clean with warm, soapy water and a soft brush. Avoid ultrasonic cleaners, as the vibrations can cause fractures in already-chipped stones. * Storage: Store separately in a soft cloth to prevent scratches from other gems.
Tanzanite Care Tanzanite’s relative softness and cleavage make it vulnerable. * Cleaning: Use only mild soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaners, which can cause damage. * Storage: Store in a padded jewelry box, wrapped in a soft cloth. It should be kept away from harder gems that could scratch it. * Setting: It is best set in protective settings like bezels for rings, or in pendants and earrings where it is less likely to be knocked.
Blue Topaz Care As the hardest of the December stones, Blue Topaz is the most resilient. * Cleaning: It can be safely cleaned with warm, soapy water, a soft brush, and even an ultrasonic cleaner (if the stone is not fractured). Avoid sudden temperature changes. * Storage: While durable, it should still be stored separately to prevent scratching other softer stones.
Conclusion
December’s birthstones offer a remarkable diversity, from the ancient, opaque charm of Turquoise to the fiery brilliance of Zircon, the transformative violet-blue of Tanzanite, and the durable, sky-blue clarity of Blue Topaz. Each gemstone tells a story of geological wonder, human history, and cultural belief. Their collective blue palette perfectly captures the essence of the winter month, providing options for every preference, budget, and style. Whether chosen for its historical significance, its modern allure, its durability, or its metaphysical properties, any of these four gemstones serves as a meaningful and beautiful connection to the month of December. Understanding their unique properties, origins, and care requirements ensures that these treasures can be appreciated and preserved for generations to come.