The final month of the year is uniquely distinguished in the world of gemology by its abundance of official birthstones. While many months are associated with a single gem, December boasts a quartet of captivating blue stones: Turquoise, Tanzanite, Zircon, and Blue Topaz. This remarkable variety offers those born in the month unparalleled choice, reflecting the diverse and multifaceted nature of the winter season itself. Each of these gems possesses a distinct history, a unique set of physical properties, and a rich tapestry of symbolism, making them subjects of enduring fascination for collectors, jewelers, and enthusiasts alike. The tradition of multiple birthstones for December is a relatively modern development, driven by a desire to provide more options in terms of color, style, and affordability, ensuring that every December-born individual can find a personal talisman that resonates with their individuality.
The journey of December's birthstones is one that spans from ancient civilizations to modern-day mines, from protective amulets to symbols of transformation and clarity. The cool, serene blues of these gems evoke images of icy landscapes, deep winter skies, and the tranquil beauty of the season. Understanding the nuances of each stone—from the historic allure of Turquoise to the recent discovery of Tanzanite, the brilliant fire of Zircon, and the dependable durability of Blue Topaz—is essential for appreciating their full significance. This comprehensive guide will delve into the history, geological origins, gemological properties, and symbolic meanings of each of December's four official birthstones, providing an expert perspective for anyone looking to connect more deeply with these remarkable treasures of the earth.
The Historical Tapestry and Evolution of a Tradition
The concept of birthstones is rooted in ancient history, most notably the biblical description of the High Priest Aaron's breastplate, which was adorned with twelve different gemstones representing the twelve tribes of Israel. This tradition was later adapted into a more personal practice, with individuals wearing a different gemstone each month. However, the modern list of birthstones as we know it today was standardized in 1912 by the National Association of Jewelers (now known as the Jewelers of America) in an effort to create a practical and commercially viable guide for the American jewelry industry.
Initially, the 1912 list included only Turquoise and Blue Topaz for the month of December. This list has since evolved to reflect new discoveries and changing tastes. In 1952, the Jewelry Industry Council of America updated the list, adding Zircon to December's offerings. Decades later, in 2002, the American Gem Trade Association (AGTA) and the Jewelers of America officially added Tanzanite, recognizing its growing popularity and significance in the gem market. This evolutionary process highlights how birthstone traditions are not static but are living customs that adapt to incorporate new and significant gemological finds. The addition of multiple stones for December was a deliberate choice, likely intended to provide a wider spectrum of blue hues and to offer gems at various price points, making birthstone jewelry more accessible to a broader audience. The result is a month uniquely endowed with a diverse palette of blue gems, each with its own story and appeal.
Turquoise: The Ancient Talisman
History and Lore
Turquoise is arguably the most ancient of all December's birthstones, with a history of human use and admiration that spans millennia. Its name is derived from the French phrase pierre turquoise, meaning "Turkish stone," as the gem was first brought to Europe from Turkey via the Persian trade routes. However, Turquoise has been mined and cherished in regions far beyond Turkey. It has been a cornerstone of decorative and spiritual life for numerous cultures, including the ancient Egyptians, Persians, and Native American peoples of the American Southwest. For these civilizations, Turquoise was more than just an ornament; it was a powerful protective talisman, a conduit for communication with the divine, and a symbol of wealth and status. It was believed to ward off evil, ensure safety during travel, and bring good fortune and health to the wearer. The iconic sky-blue to greenish-blue hues of Turquoise were seen as a reflection of the heavens, making it a sacred stone that connected the earthly and celestial realms.
Geological Formation and Sources
Turquoise is a secondary mineral that forms when water containing copper, aluminum, and iron seeps through pre-existing rock. This process occurs in arid regions where the water table can interact with these minerals over millions of years, creating veins and nodules of the gemstone. The specific mineral content of the water and surrounding rock determines the final color of the stone, with copper producing the most prized sky blues and iron contributing to greenish shades. The most significant historical and modern sources for Turquoise are located in the United States (particularly Arizona, New Mexico, and Nevada), Iran, and China. The material from these regions varies in color, matrix (the host rock embedded within the turquoise), and durability, leading to a wide variety of grades and styles.
Gemological Properties
Turquoise is an opaque gemstone with a distinctive waxy to vitreous luster. Its chemical composition is a hydrated phosphate of copper and aluminum. On the Mohs scale of hardness, Turquoise typically ranges from 5 to 6, making it relatively soft compared to other gemstones. This moderate hardness means it is susceptible to scratching and can be damaged by chemicals, heat, and prolonged exposure to sunlight, which can cause its color to fade. Due to its porous nature, Turquoise is often stabilized with wax or resin to enhance its durability, improve its polish, and lock in its color. The most valuable Turquoise exhibits a uniform, intense sky-blue color with no matrix or a desirable, intricate web-like matrix.
Tanzanite: The Modern Marvel of a Single Source
History and Lore
In stark contrast to the ancient lineage of Turquoise, Tanzanite is a newcomer to the gemological world. This vivid gem was first discovered in the Merelani foothills of Mount Kilimanjaro in Tanzania in the late 1960s. Its discovery is a relatively recent event, making it one of the most significant gemstone finds of the 20th century. The gem's rapid rise to fame was fueled by the Tiffany & Co. jewelry company, which recognized its unique beauty and began a major marketing campaign in 1968, naming it after its country of origin. Due to its limited geographic origin and stunning color, it is often described as "a generation stone," as it is believed that the source will be depleted within a few decades, making it exceptionally rare. This rarity contributes to its high value and desirability. Metaphysically, Tanzanite is associated with transformation, intuition, and spiritual awakening, believed to facilitate a higher consciousness and a deeper connection to one's inner truth.
Geological Formation and Sources
Tanzanite's formation is as unique as its color. It is a variety of the mineral zoisite and owes its captivating violet-blue hue to trace amounts of vanadium. The gem is found in only one place on Earth: a small, four-square-kilometer mining area in the Merelani region of northern Tanzania. The geological conditions required for its creation were exceptionally rare, occurring as a result of a massive tectonic plate shift and metamorphic event that pushed the mineral-rich rock to the surface. This single-source origin makes Tanzanite exceptionally rare, a fact that significantly drives its market value and prestige.
Gemological Properties
Tanzanite is known for its strong trichroism, a property that allows it to display three different colors when viewed from different angles: blue, violet, and a reddish-purple. The most sought-after color is a deep, rich violet-blue. It has a Mohs hardness of 6.5 to 7, which is moderately durable but still requires careful handling to prevent scratching or chipping. Most Tanzanite available on the market has been heat-treated to achieve its stable blue and violet colors; untreated material is typically brownish or greenish. This heat treatment is a standard, permanent practice and is widely accepted in the gem trade.
Zircon: The Brilliant Imitator with a Rich Past
History and Lore
Zircon is one of the oldest minerals on Earth, with crystals dating back billions of years. For centuries, it has been prized for its exceptional brilliance and fire, which often rivals that of diamond. In the Middle Ages, Zircon was believed to induce sleep, ward off evil spirits, and bring prosperity and honor to its wearer. Its name is thought to be derived from the Persian word zargun, meaning "gold-colored," though Zircon occurs in a variety of colors. The blue variety of Zircon, which is the most common for December birthstones, is often heat-treated to achieve its beautiful color. It is important to distinguish natural Zircon from the synthetic material cubic zirconia (CZ), which was developed as a diamond simulant and has no relation to natural Zircon other than a phonetic similarity.
Geological Formation and Sources
Zircon is a mineral belonging to the group of nesosilicates. It is a primary crystal that forms within igneous and metamorphic rocks during their initial crystallization. This makes it one of the first minerals to form as magma cools. Its remarkable durability and resistance to chemical and physical weathering allow it to survive for eons, making it a valuable tool for geologists in dating rocks (geochronology). Significant sources for gem-quality Zircon are found in Sri Lanka, Thailand, Cambodia, and Australia. The blue Zircon used in jewelry is typically produced by heating brownish or greenish Zircon from Cambodia or Vietnam to high temperatures, a process that permanently removes the undesirable color tones.
Gemological Properties
Zircon is celebrated for its exceptional optical properties. It has a very high refractive index (2.4), which is higher than that of sapphire and diamond, giving it outstanding brilliance and fire. It also exhibits strong birefringence (double refraction), which can sometimes be observed with the naked eye as a doubling of the gem's facet edges. On the Mohs scale, Zircon has a hardness of 7.5, making it one of the harder and more durable of the December birthstones, suitable for a variety of jewelry applications, though its natural cleavage (a tendency to break along flat planes) requires care during cutting and setting. The most prized Zircon color is a vivid, pure blue, often referred to as "Maturi Blue" after the Sri Lankan mining region.
Blue Topaz: The Durable and Affordable Blue
History and Lore
Blue Topaz has a long but somewhat mysterious history. The name "topaz" is believed to originate from the Sanskrit word tapas, meaning "fire," or from the Greek island of Topazos in the Red Sea, where a yellow stone (now believed to be peridot) was mined. Throughout history, blue topaz has been found, but its exact origins are often unclear, as many historical blue gems were mistakenly identified. Unlike the other December stones, Blue Topaz is not associated with a single, dramatic discovery story but has been a consistent presence in the gem world. It is the official state gem of Texas, a nod to its significance in the United States. In modern times, it is often associated with clarity of thought, calmness, and communication.
Geological Formation and Sources
Topaz is a silicate mineral of fluorine and aluminum that forms in igneous rocks, particularly in pegmatites and vapor-rich cavities in rocks like rhyolite. Natural blue topaz is extremely rare; the vast majority of blue topaz on the market is created by irradiating and heat-treating colorless or pale topaz. This process is stable and permanent. Major mining locations for topaz include Sri Lanka, Brazil, Mexico, Nigeria, and the United States.
Gemological Properties
Blue Topaz is the most durable of the December birthstones for everyday wear. It ranks an 8 on the Mohs hardness scale, making it highly resistant to scratching and ideal for rings and other jewelry that see frequent use. It has a vitreous luster and is typically found in large, clean crystals, which makes it an excellent choice for larger, statement jewelry pieces. The color of treated blue topaz can range from a light, icy blue (known as "Sky Topaz") to a deep, saturated "London Blue" or "Swiss Blue," depending on the intensity of the treatment process.
Comparative Gemological Properties
To provide a clear overview of the physical characteristics of each December birthstone, the following table summarizes their key gemological properties as detailed in the provided sources.
| Gemstone | Mohs Hardness | Chemical Composition | Typical Color(s) | Key Characteristics | Durability for Daily Wear |
|---|---|---|---|---|---|
| Turquoise | 5 - 6 | Hydrated phosphate of copper and aluminum | Sky blue to greenish-blue | Opaque, often contains a matrix, porous | Moderate; susceptible to scratching and chemicals |
| Tanzanite | 6.5 - 7 | Calcium aluminum hydroxyl sorosilicate | Violet-blue, trichroic (blue, violet, red) | Strong trichroism, often heat-treated | Fair to good; requires careful handling |
| Zircon | 7.5 | Zirconium silicate | Blue (often heat-treated), also brown, green | High refractive index, strong fire, natural cleavage | Good; durable but can be brittle due to cleavage |
| Blue Topaz | 8 | Aluminum silicate with fluorine and hydroxyl | Light blue to deep saturated blue | Large, clean crystals available, treated for color | Excellent; very hard and resistant to wear |
Metaphysical Beliefs and Symbolism
Beyond their physical beauty, each of December's birthstones carries a rich legacy of symbolic meaning and metaphysical belief. These meanings have been passed down through generations and continue to be a significant factor for many people when choosing their birthstone.
- Turquoise is universally regarded as a stone of protection, wisdom, and good fortune. It is believed to shield the wearer from negative energy, promote inner calm, and foster clear communication. For centuries, it has been a talisman for travelers and a symbol of prosperity.
- Tanzanite, with its recent discovery, is associated with modern metaphysical concepts. It is known as a stone of transformation, spiritual insight, and intuition. It is said to open the mind to new possibilities, facilitate a connection to one's higher self, and encourage a calm, centered state of being.
- Zircon is linked to clarity, wisdom, and honor. It is believed to help clear the mind of negative thoughts, enhance spiritual awareness, and attract prosperity and honor to the wearer. Its brilliant sparkle is thought to represent a clear and focused state of mind.
- Blue Topaz is associated with calmness, clarity, and emotional balance. It is believed to soothe frayed nerves, aid in clear communication, and promote truth and forgiveness. Its tranquil blue hue is seen as a source of peace and tranquility.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of gemstone jewelry. The varying hardness and durability of December's birthstones necessitate different care considerations.
- Turquoise: Due to its porosity and moderate hardness, Turquoise should be protected from chemicals, perfumes, and prolonged exposure to sunlight. Clean it gently with warm, soapy water and a soft cloth. Avoid ultrasonic cleaners and steam cleaners.
- Tanzanite: With a Mohs hardness of 6.5 to 7, Tanzanite is relatively durable but can be chipped by a hard blow. It is best cleaned with warm, soapy water and a soft brush. Avoid sudden temperature changes and ultrasonic cleaners.
- Zircon: Although Zircon is fairly hard (7.5), it has natural cleavage, making it susceptible to breaking if struck with force. It is advisable to avoid ultrasonic cleaners. Clean with warm, soapy water and a soft brush, taking care not to subject the stone to pressure.
- Blue Topaz: As the hardest of the group (8), Blue Topaz is quite durable and suitable for everyday wear. It can be cleaned safely with warm, soapy water, an ultrasonic cleaner, and even a steam cleaner, making it one of the easiest of the December stones to maintain.
Conclusion
The month of December is uniquely blessed with a quartet of exceptional blue gemstones, each offering a distinct blend of beauty, history, and durability. From the ancient protective powers of Turquoise to the rare, transformative elegance of Tanzanite, the brilliant fire of Zircon, and the dependable clarity of Blue Topaz, these stones provide a remarkable range of choices for those born in the final month of the year. The evolution of the December birthstone list reflects a dynamic tradition that embraces both historical significance and modern discovery, ensuring that every individual can find a gem that speaks to them. Whether chosen for its metaphysical properties, its historical lore, or simply its captivating color, a December birthstone is more than just a piece of jewelry; it is a personal emblem of the cool, reflective, and deeply meaningful essence of winter.