The vibrant blue-green hues of turquoise have captivated humanity for millennia. As the primary birthstone for December, this opaque gemstone carries a legacy woven through ancient civilizations, geological marvels, and enduring symbolism. While December boasts multiple birthstones—turquoise, tanzanite, zircon, and blue topaz—turquoise stands out for its rich historical tapestry and cultural significance across the globe. Its journey from the mines of Persia to the jewelry boxes of modern December celebrants is a story of geological alchemy, human reverence, and timeless beauty. This article delves into the history, formation, properties, and care of turquoise, exploring why it remains a cherished emblem for those born in the final month of the year.
History and Lore: A Stone of Joy and Status
Turquoise is one of the oldest known gemstones, with evidence of its use dating back over 6,000 years. Archaeological discoveries have unearthed turquoise jewelry in ancient Egyptian tombs from as early as 3000 BCE. The ancient Egyptians held the stone in high regard, calling it mefkat, which translates to “joy” and “delight.” Far more than a mere adornment, turquoise was a potent symbol of status, prosperity, and protection in Egyptian society, often placed with the deceased to ensure safe passage to the afterlife.
The stone’s influence extended beyond the Nile Valley. In ancient Mesopotamia, the region between the Tigris and Euphrates rivers, turquoise was a prized commodity. By the 13th century BCE, Persian turquoise from what is now Iran was being traded extensively along ancient routes. The deep, vivid blue of Persian turquoise became the benchmark for quality, a shade so distinctive that it earned the name “Persian blue” and remains highly coveted by collectors and jewelers today.
Across the Atlantic, turquoise held profound importance in the Americas. The Aztecs incorporated the stone into their elaborate mosaic art and ceremonial jewelry, using it to adorn royalty and sacred objects. When Spanish conquistadors arrived in the New World, they were astounded by the opulent turquoise finery worn by Aztec leaders, which signaled both immense wealth and spiritual power. For numerous Native American tribes across North America, turquoise was not just a gemstone but a sacred element of cultural and spiritual life. It was believed to be a piece of the sky that had fallen to earth, connecting the wearer to the heavens and offering protection from harm. This deep-rooted reverence established turquoise as a stone of wisdom, good fortune, and healing across diverse cultures.
The modern designation of turquoise as a December birthstone is a relatively recent development, part of a standardized list created in the early 20th century. In 1912, the National Association of Jewelers in the United States sought to formalize the unofficial tradition of birthstones, creating a list that combined historical customs with gemstones practical for commercial jewelry. Turquoise was included for December, cementing its place in contemporary jewelry culture. While other stones like zircon and tanzanite were added to the December list in later years (1952 and 2002, respectively), turquoise remains the traditional and most historically significant choice.
Geological Formation and Sources: The Chemistry of Color
Turquoise is a secondary mineral, meaning it does not form from the cooling of magma but through a chemical reaction in the earth's upper crust. Its formation is a slow process requiring a specific combination of elements. Groundwater, rich in copper, seeps through pre-existing rock formations, often in arid regions. As this copper-laden water interacts with minerals containing aluminum and phosphorus, a chemical reaction occurs over thousands of years, precipitating the hydrated phosphate of copper and aluminum that constitutes turquoise.
The presence of copper is responsible for the gemstone’s characteristic blue and blue-green colors. The intensity of the blue is directly related to the copper content; higher copper levels yield a more vivid blue. Green hues appear when iron replaces some of the copper in the crystal structure, or when the stone is formed in a different mineral environment. The dark, web-like lines and patches often seen in turquoise are not flaws but are part of the stone’s character. Known as the matrix, this is the host rock that was present during the turquoise’s formation, and it becomes an integral part of the gem, influencing its pattern and sometimes its color.
Turquoise is typically found in nodules or veins within a porous rock matrix. Because it is relatively soft and can be brittle, large, clean pieces suitable for faceting are exceptionally rare. Most turquoise is cut into cabochons (smooth, rounded domes) for use in jewelry, which best showcases its opaque beauty and color.
The primary sources of natural turquoise are concentrated in a few key regions around the world:
- Iran (Persia): Historically the most famous source, producing the classic “Persian blue” turquoise. The mines in the Nishapur region have been operational for centuries and are known for producing stones with a uniform, sky-blue color and minimal matrix.
- Southwestern United States: The American Southwest, particularly Arizona, New Mexico, and Nevada, is home to a rich tradition of turquoise mining and use by Native American cultures. Mines such as the Sleeping Beauty, Kingman, and Morenci produce turquoise with distinct color characteristics, often with a matrix. The "robin's egg blue" of the Sleeping Beauty mine is particularly renowned.
- Egypt: The ancient source of mefkat, Egyptian turquoise is often a lighter, greenish-blue and is frequently found with a dark, spiderweb matrix.
- China: Chinese turquoise mines produce a range of qualities, from soft, light-blue stones to more vivid colors, often stabilized for commercial use.
- Other Notable Sources: Afghanistan, Chile, and Australia also contribute to the global supply, each yielding stones with unique local characteristics.
Gemological Properties: The Science of an Opaque Gem
Understanding turquoise’s physical and chemical properties is essential for appreciating its characteristics, value, and care requirements. As an opaque gemstone, its beauty is judged primarily by its color, uniformity, and the texture of its matrix, rather than clarity and brilliance as in transparent gems.
Chemical and Physical Characteristics: Turquoise is a hydrous phosphate of copper and aluminum, with the chemical formula CuAl₆(PO₄)₄(OH)₈·4H₂O. This complex formula reflects its formation process, which incorporates water into its crystal structure. The presence of water makes turquoise susceptible to heat and chemical changes, a critical factor in its care.
Its hardness on the Mohs scale ranges from 5 to 6. This places it in the moderate range, making it softer than quartz (7) but harder than gypsum (2). This relative softness means it can be scratched by harder materials, including everyday dust and dirt. Its toughness is also a consideration; while it is relatively tough for an opaque mineral, it has poor cleavage, meaning it can fracture if struck with sufficient force along certain planes. This inherent fragility necessitates protective jewelry settings and careful handling.
Color and Clarity: The color spectrum of turquoise is vast, ranging from sky blue to apple green, with every shade in between. The most prized color is a uniform, medium to dark sky blue, often described as "robin's egg blue." The presence of the matrix—whether black, brown, or golden—adds complexity and character. Some collectors prefer stones with a clear, uniform color (often called "clear" or "light" matrix), while others value the intricate patterns of a dark matrix.
Treatments and Enhancements: Natural, high-quality turquoise is exceptionally rare. To meet commercial demand and improve durability and color, most turquoise on the market undergoes some form of stabilization or enhancement. Common treatments include: * Waxing or Oiling: Applying wax or oil to the surface to enhance color and luster. This is a temporary treatment and may require reapplication. * Stabilization: Impregnating the stone with a clear resin or plastic under pressure. This process fills the pores, making the stone harder, more durable, and less prone to absorbing skin oils or chemicals. Stabilized turquoise is more stable and easier to care for but is generally less valuable than natural, untreated stone. * Reconstituted Turquoise: Made from powdered turquoise mixed with a binder and dyed. This material is not natural turquoise but an imitation. * Imitation Turquoise: Materials like plastic, glass, or dyed howlite or magnesite are often used to simulate the appearance of turquoise.
Value and Rarity: The price of turquoise varies dramatically based on color, matrix, origin, size, and treatment. High-quality, natural Persian or rare American turquoise can command prices of over $1,000 per carat. More common, stabilized turquoise is significantly more affordable, often ranging from $5 to $50 per carat. The rarity of natural, untreated stones makes them highly collectible.
Symbolism and Metaphysical Beliefs: A Stone of Protection and Renewal
Beyond its physical beauty, turquoise is steeped in symbolism and metaphysical lore that spans cultures and millennia. Its meanings are as diverse as its sources, yet they often converge on themes of protection, wisdom, and positive energy.
In ancient Egypt, it was a stone of joy and protection. For Native American tribes, particularly the Navajo, Zuni, and Pueblo peoples, turquoise is a sacred stone, often called the "sky stone." It is believed to connect the wearer to the spiritual world, offer protection from evil spirits, and bring good health and fortune. Many tribes use turquoise in ceremonies and consider it a vital component of their cultural identity.
Across various cultures, turquoise has been associated with: * Protection: Worn as an amulet to guard against accidents, violence, and negative energies. * Wisdom and Truth: Believed to enhance mental clarity, honesty, and clear communication. * Healing and Balance: Thought to have calming energies that soothe the mind and body, and to support the immune system. * Good Fortune and Prosperity: Carried to attract wealth, success, and happiness.
In modern crystal healing practices, turquoise is often linked to the throat chakra, associated with communication and self-expression, and the heart chakra, associated with love and compassion. It is also considered a birthstone for Sagittarius and Pisces, and is traditionally given as a gift for the 11th wedding anniversary.
For December babies, turquoise symbolizes the month’s cool, clear skies and the promise of renewal. Its blue-green color is reminiscent of winter ice and evergreen foliage, making it a fitting emblem for the season. The stone’s lore of protection and good fortune offers a meaningful sentiment for a birthday gift, wishing the wearer safety, happiness, and success in the year ahead.
Care and Cleaning: Preserving a Delicate Beauty
Given its moderate hardness and porosity, turquoise requires specific care to maintain its color and structural integrity. Proper maintenance is crucial to prevent damage, discoloration, and loss of luster.
Key Care Guidelines: 1. Avoid Chemicals: Turquoise is highly susceptible to chemicals found in everyday products. This includes cosmetics, perfumes, hairsprays, lotions, and cleaning agents. These substances can cause the stone to discolor, become dull, or even crack. It is advisable to put on turquoise jewelry after applying makeup and perfumes and to remove it before household cleaning. 2. Protect from Heat and Sunlight: Prolonged exposure to direct sunlight or high heat (such as in an oven or near a heater) can cause the stone to lose its color and become brittle. Do not leave turquoise jewelry in a hot car or on a sunny windowsill. 3. Clean Gently: Never use an ultrasonic cleaner, steam cleaner, or harsh chemical cleaners on turquoise. The vibrations and heat can damage the stone and any treatments. Instead, clean it with a soft, damp cloth. Use mild soap if necessary, but rinse thoroughly and dry immediately with a soft, lint-free cloth. 4. Store Properly: Store turquoise jewelry separately from other gems and metals to prevent scratches. A soft pouch or a lined jewelry box is ideal. Avoid storing it in a dry, hot environment like a safe deposit box for long periods, as extreme dryness can cause some untreated stones to crack. 5. Handle with Care: Due to its relative softness and brittleness, avoid wearing turquoise jewelry during activities that could cause impact or abrasion, such as gardening, sports, or heavy manual work.
For stabilized turquoise, care is somewhat easier as the resin impregnation makes it more resistant to chemicals and moisture. However, the same precautions should still be followed to ensure the stone’s longevity.
Conclusion
Turquoise is far more than a simple blue-green gemstone. It is a geological marvel, a historical artifact, and a cultural touchstone. From the tombs of Egyptian pharaohs to the ceremonial jewelry of Native American tribes, its journey through human history is a testament to its enduring appeal. Its unique formation process gives rise to a spectrum of captivating colors and patterns, each stone a one-of-a-kind piece of natural art. While its moderate hardness requires mindful care, its symbolic weight—representing protection, wisdom, and good fortune—makes it a deeply meaningful choice for jewelry, especially as the birthstone for December. Whether admired for its scientific properties, its rich lore, or its sheer aesthetic beauty, turquoise continues to inspire and delight, securing its place as one of the world’s most cherished and storied gemstones.