December holds a unique distinction in the world of birthstones. While most months are assigned a single gem, December boasts a diverse quartet of blue-hued stones: Turquoise, Zircon, Tanzanite, and Blue Topaz. This abundance offers a spectrum of choices, from ancient talismans to modern marvels, each with its own history, geological origin, and symbolic meaning. For those born in the final month of the year, the question is not "what is the birthstone," but rather "which blue speaks to me?" This comprehensive guide explores the gemological properties, historical significance, and cultural lore of each of December's four official birthstones, providing an expert perspective for enthusiasts, collectors, and jewelry buyers alike.
The tradition of birthstones can be traced back thousands of years, with roots in ancient civilizations like Egypt, Greece, and Rome, where gemstones were believed to possess mystical and healing properties. Over time, these beliefs evolved into a standardized list, influenced by commercial interests and evolving gemological discoveries. The modern list for December, as recognized by the Gemological Institute of America (GIA), includes Turquoise, Zircon, and Tanzanite. However, Blue Topaz has gained significant popularity and is now frequently considered a mainstream modern birthstone, expanding the options for December-born individuals. This expansion offers consumers greater flexibility in terms of price, durability, and personal style.
The common thread among these gems is their blue coloration, a hue that evokes the cool, serene imagery of winter. From the soft, sky-blue of Turquoise to the deep, shifting violet-blue of Tanzanite, each stone captures a different facet of December's chill beauty. This article will delve into the history and lore of each gem, examine its geological formation and primary sources, detail its key gemological properties, discuss its symbolism, and provide practical advice for care and cleaning. By understanding the unique attributes of each stone, one can make an informed and meaningful choice that resonates with personal preference and aesthetic.
History and Lore: From Ancient Talismans to Modern Gems
The history of December's birthstones is a tapestry woven from ancient beliefs, royal endorsements, and modern marketing. Each stone carries a legacy that spans continents and centuries, contributing to its status as a birthstone.
Turquoise is arguably the oldest of the December stones, with a history dating back over 6,000 years. It was cherished by ancient Egyptian, Persian, and Chinese civilizations, often used in ornamental objects and jewelry for protection and good fortune. Its name is derived from the French pierre turquoise, meaning "Turkish stone," as it was brought to Europe from Persia via Turkey. For many Native American cultures, particularly in the American Southwest, Turquoise is a sacred stone symbolizing life, health, and protection. Its journey to becoming a recognized birthstone is rooted in these ancient traditions, making it a stone of profound historical significance.
Zircon has a history almost as long, with its name believed to be derived from the Arabic zarkun, meaning "vermillion" or "gold-colored," though it is most famous today for its blue variety. For centuries, Zircon was mistaken for other gemstones, notably diamond, due to its high refractive index and brilliance. In the Middle Ages, Zircon was believed to promote rest, aid in spiritual growth, and ward off evil spirits. The blue variety, which is the standard for December, is typically produced by heat-treating brown Zircon, a process that has been practiced for centuries. Its inclusion in the birthstone list was formalized in 1952 by the Jewelry Industry Council of America, adding a gem of exceptional sparkle to the December palette.
Tanzanite is the newest addition to the birthstone family, discovered in 1967 in the Merelani Hills of Tanzania. Its rapid rise to prominence is a modern gemological success story. The stone was quickly recognized for its unique, intense violet-blue color and was first marketed as a birthstone for December in 2002 by the Jewelry Industry Council of America. Its rarity—found only in a single small mining area—has contributed to its allure and value. Unlike the ancient stones, Tanzanite's lore is contemporary, often associated with transformation and new beginnings, reflecting its recent discovery and dramatic appearance.
Blue Topaz, while the newest in terms of commercial popularity, has an ancient etymology. The name "Topaz" is believed to originate from the Greek Topazios, the ancient name of an island in the Red Sea (now St. John's Island). However, historical accounts suggest that the stones mined there were actually Peridot, not Topaz. Despite this confusion, Topaz has been valued since antiquity for its various colors. The blue variety, however, is a product of modern gemology. Naturally occurring blue Topaz is exceedingly rare; most blue Topaz on the market is created by irradiating and heat-treating colorless Topaz. Its status as a modern birthstone was solidified in the late 20th century as it gained popularity for its bright, clear blue color and affordability. It was officially named the state gem of Texas, further cementing its place in American gem culture.
Geological Formation and Global Sources
Understanding where these gemstones come from provides insight into their rarity and value. Each of the December stones forms under distinct geological conditions and is sourced from specific, often limited, locations around the world.
Turquoise is a secondary mineral formed by the percolation of water through rocks rich in copper and aluminum. This process occurs in arid regions where evaporation concentrates the minerals, leading to the deposition of Turquoise nodules or veins in host rock. The most famous sources are in the American Southwest (Arizona, New Mexico, Nevada), Iran, and Tibet. The color of Turquoise is directly influenced by the presence of copper (blue) and iron (green), resulting in its characteristic sky-blue to greenish hues. Its formation is slow, and high-quality, uniform Turquoise is becoming increasingly scarce.
Zircon is a zirconium silicate mineral that crystallizes from magma in igneous and metamorphic rocks. It is one of the oldest minerals on Earth, with some crystals dating back billions of years. For gemstone purposes, the primary sources of Zircon are alluvial deposits, where it has been eroded from its original host rock and concentrated in riverbeds. Major sources include Sri Lanka, Cambodia, Myanmar, and Australia. The blue variety is typically produced by heating brown Zircon from Cambodia or Myanmar, which is the most common source for gem-quality blue Zircon.
Tanzanite is a variety of the mineral zoisite. It is formed by a unique geological process involving the intense heat and pressure from the tectonic collision of the African and European plates. This event, which occurred approximately 585 million years ago, created the specific conditions for the formation of Tanzanite in the Merelani Hills of Tanzania. The stone is only found in this single, small mining area, making it rarer than diamond. The mining is challenging and often hazardous, contributing to its scarcity and high value. The intense blue-violet color is a result of trace vanadium within the mineral's structure, a color that is further enhanced by heat treatment.
Blue Topaz is a variety of the mineral topaz, which crystallizes in igneous rocks, particularly in cavities within granite and rhyolite. Naturally occurring blue Topaz is exceptionally rare. The vast majority of blue Topaz on the market is created by treating colorless or pale blue Topaz. The process involves irradiating the stone to create a brown color, followed by heating to transform it into a stable blue. The primary sources for the colorless Topaz used in this process are Sri Lanka, Brazil, Mexico, Nigeria, and the United States (specifically Texas, Utah, and California). The treatment is permanent and is a standard industry practice, making blue Topaz widely available and affordable.
Gemological Properties: A Scientific Comparison
The gemological properties of a stone determine its durability, appearance, and value. The following table compares key properties of the four December birthstones based on the provided sources.
| Gemstone | Chemical Composition | Mohs Hardness | Refractive Index | Key Characteristics |
|---|---|---|---|---|
| Turquoise | Hydrated copper aluminum phosphate (CuAl₆(PO₄)₄(OH)₈·4H₂O) | 5 - 6 | 1.61 - 1.65 | Often contains a matrix (host rock) and can be porous. Color ranges from sky blue to green. |
| Zircon | Zirconium silicate (ZrSiO₄) | 6.5 - 7.5 | 1.92 - 2.01 | High refractive index and strong dispersion ("fire"), often mistaken for diamond. |
| Tanzanite | Calcium aluminum silicate (Ca₂Al₃(SiO₄)₃(OH)) | 6.5 - 7 | 1.69 - 1.70 | Pleochroic, showing different colors (blue, violet, burgundy) from different angles. |
| Blue Topaz | Aluminum silicate with fluorine and hydroxyl (Al₂SiO₄(F,OH)₂) | 8 | 1.61 - 1.63 | Typically treated to achieve its blue color. Naturally occurring blue is very rare. |
Turquoise is the softest of the four, with a Mohs hardness of 5 to 6. This makes it susceptible to scratching and abrasion, requiring careful handling. Its chemical composition is hydrated, meaning it can lose water and change color if exposed to heat, chemicals, or prolonged sunlight. The presence of a matrix (the host rock in which it formed) is common and can be a desirable feature, adding unique patterns to the stone.
Zircon is notably harder than Turquoise, with a Mohs hardness of 6.5 to 7.5, making it more durable for jewelry. Its most remarkable property is its high refractive index (1.92 - 2.01), which is higher than that of diamond, and its strong dispersion, which gives it exceptional "fire" or sparkle. This brilliance is why it has historically been mistaken for diamond. However, Zircon can be brittle due to its tetragonal crystal structure, making it prone to chipping if struck.
Tanzanite has a Mohs hardness of 6.5 to 7, placing it in a moderate durability range. It is not recommended for rings worn daily due to the risk of chipping and abrasion. Its most distinctive gemological property is its strong pleochroism. When viewed from different angles, it can display three different colors: blue, violet, and a reddish-brown. Gem cutters orient the stone to show the desired blue-violet hue, often with a cut designed to minimize the visibility of the other colors.
Blue Topaz is the most durable of the December stones, with a Mohs hardness of 8. This makes it an excellent choice for everyday jewelry, such as rings and bracelets, as it is resistant to scratching and abrasion. Its refractive index is similar to that of Turquoise (1.61 - 1.63), but its greater hardness and clarity give it a brighter, more sparkling appearance. The vast majority of blue Topaz is treated, and this treatment is stable and permanent, making it a reliable and consistent gem for jewelry.
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, these stones are imbued with symbolic meanings and metaphysical beliefs that have been passed down through generations.
Turquoise is universally regarded as a stone of protection, healing, and good fortune. It is often called a "sky stone" for its connection to the heavens. In many cultures, it is believed to ward off negative energy, promote emotional balance, and bring peace to the wearer. Its association with protection makes it a popular amulet for travelers and warriors. Metaphysically, Turquoise is said to align and balance the chakras, particularly the throat and heart chakras, fostering honest communication and compassion.
Zircon is associated with clarity, wisdom, and balance. Its brilliant sparkle is thought to inspire spiritual growth and mental clarity. In some traditions, it is believed to promote restful sleep and protect against nightmares. The blue variety, in particular, is linked to calmness and stability, helping to soothe overactive minds and bring a sense of order and peace. It is also said to attract prosperity and success, making it a stone of both spiritual and material well-being.
Tanzanite, as a modern discovery, has developed a contemporary symbolism centered on transformation, intuition, and new beginnings. Its unique color, which shifts with the light, is seen as a metaphor for the multifaceted nature of life and the ability to see beyond the obvious. It is believed to open the mind to higher consciousness, enhance spiritual perception, and facilitate a connection with one's inner self. As a stone of 2002, it is also associated with the modern era of change and evolution.
Blue Topaz symbolizes love, fidelity, and calmness. Its serene blue color is associated with tranquility, truth, and clear communication. It is often given as a gift to express deep affection and commitment. Metaphysically, Blue Topaz is believed to calm the mind, reduce stress, and promote feelings of joy and generosity. It is also associated with the throat chakra, enhancing the ability to express oneself clearly and confidently. Its durability is often linked to the strength and resilience of love and friendship.
Care and Cleaning: Preserving Your December Gem
Proper care is essential to maintain the beauty and longevity of any gemstone. The varying hardness and chemical stability of the December stones require specific cleaning methods and handling precautions.
Turquoise is the most delicate of the four and requires the most care. It should be protected from harsh chemicals, including household cleaners, perfumes, and lotions, which can cause discoloration and damage. Avoid prolonged exposure to direct sunlight, as it can fade the color. Clean Turquoise with a soft, damp cloth and mild soap, then dry immediately. Store it separately from other jewelry to prevent scratching. It is not recommended for ultrasonic or steam cleaners.
Zircon is relatively durable but can be brittle. It should be protected from sharp blows and extreme temperature changes, which can cause cracking. Clean Zircon with warm water, a mild detergent, and a soft brush. It is generally safe for ultrasonic cleaners, but caution is advised if the stone has fractures or inclusions. Avoid sudden temperature changes during cleaning.
Tanzanite requires gentle handling due to its moderate hardness and cleavage. It should not be exposed to harsh chemicals or extreme heat. Clean it with warm, soapy water and a soft brush, avoiding pressure on the stone. Ultrasonic cleaners and steam cleaners are not recommended, as the vibrations and heat can cause damage. Store Tanzanite jewelry in a soft cloth to prevent scratches from other gems.
Blue Topaz, with its high hardness of 8, is the most durable and easiest to care for. It can withstand daily wear and is resistant to most chemicals. Clean it with warm, soapy water and a soft brush, or use an ultrasonic cleaner. However, avoid exposing it to high heat or sudden temperature changes, as this could potentially affect the stability of the color treatment, though this is rare. Its durability makes it an excellent choice for active individuals.
Conclusion
The birthstones of December—Turquoise, Zircon, Tanzanite, and Blue Topaz—offer a remarkable diversity of color, history, and meaning. From the ancient, protective talisman of Turquoise to the brilliant, diamond-like sparkle of Zircon, the transformative violet-blue of Tanzanite, and the durable, serene blue of Topaz, each gem provides a unique option for those born in the last month of the year. Their shared blue palette reflects the winter season, while their individual stories span millennia and continents.
Choosing a December birthstone is a personal decision, influenced by factors such as budget, style preference, desired durability, and connection to a particular lore or symbolism. Whether one is drawn to the historical depth of Turquoise, the exceptional brilliance of Zircon, the modern rarity of Tanzanite, or the practical beauty of Blue Topaz, each stone carries the weight of its unique journey from the earth to the jewelry box. Understanding their gemological properties, historical contexts, and care requirements allows for an informed appreciation and ensures that these beautiful gems can be cherished for generations to come.