The month of December is uniquely adorned with not one, but two celebrated birthstones: the vibrant Turquoise and the mesmerizing Indigo Tanzanite. These gemstones, one an ancient talisman and the other a modern marvel, offer a compelling study in contrasts—from their geological origins to the symbolic meanings they hold. While Turquoise has been cherished for millennia for its protective qualities and sky-blue hue, the relatively recent discovery of Tanzanite has introduced a new dimension to December's palette with its profound indigo shades. This article explores the distinct characteristics, rich symbolism, and enduring appeal of these two remarkable gemstones, which together define the gemological identity of the year's final month.
History and Lore
The historical narratives surrounding December's birthstones are as distinct as the gems themselves. Turquoise possesses a lineage that stretches back thousands of years, while Tanzanite's story is a product of the 20th century.
Turquoise: An Ancient Talisman
Turquoise is one of the oldest known gemstones, with a history steeped in protection and power. Ancient civilizations across the globe held this stone in high esteem. The name "turquoise" itself is derived from the French phrase pierre tourques, or "Turkish stone," reflecting its introduction to Europe from Turkey via the ancient Silk Road trade routes.
For centuries, Turquoise has been regarded as a sacred stone, particularly by cultures in the Middle East, Asia, and the Americas. It was widely believed to be a powerful protector, capable of warding off evil and harm. Warriors would adorn their weapons and horses with the stone, and it was often set into rings and amulets as a shield against accidents. The ancient Persians believed that the stone's ability to change color was an indicator of its protective function, signaling that it had taken on the danger meant for its wearer. This lore of protection has made Turquoise a perennial favorite for amulets and jewelry designed for travelers and those seeking safety.
Tanzanite: A Modern Marvel
In stark contrast to Turquoise's ancient origins, Tanzanite is a newcomer to the gemstone world, its discovery dating back only to the mid-20th century. Its story began in 1967 in the Merelani Hills of northern Tanzania, near the base of Mount Kilimanjaro. A Masai herder is credited with discovering the vibrant blue crystals, which were initially mistaken for the much more common mineral sapphire.
The stone was soon identified as a variety of the mineral zoisite, and its unique, saturated violet-blue color captured the attention of the international gem market. Tiffany & Co. recognized its potential and, in 1968, named the gem "tanzanite" after its country of origin. The gemstone was heavily marketed as a "gemstone of a generation," available only in one place on Earth, which added to its mystique and allure. While it lacks the millennia of history that Turquoise enjoys, Tanzanite has rapidly established its own legacy as a celebrated and desirable modern birthstone, prized for its rarity and singular beauty.
Geological Formation and Sources
The origins of these two gemstones could not be more different, from their geological creation to the specific locations where they are found.
Turquoise: A Hydrous Phosphate
Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminum. It is a secondary mineral, meaning it is not formed directly from magma but rather through the percolation of water through rocks rich in aluminum and copper. This process occurs in arid regions, where the water evaporates and leaves behind deposits of turquoise in nodules or veins within host rock, often limonite or sandstone.
The most historically significant sources of Turquoise include ancient mines in Iran (formerly Persia), which produced the prized "Persian blue" turquoise. Other notable sources are the Southwestern United States (Arizona, New Mexico, Nevada), Egypt, and China. The color of turquoise is heavily influenced by its copper content (which imparts blue) and iron (which can create green hues). The stone's characteristic matrix—the web-like patterns of host rock—is a key identifier of its origin.
Tanzanite: A Single-Source Gemstone
Tanzanite is also a secondary mineral, but its formation is linked to a unique geological event. It is a variety of the mineral zoisite and gets its signature blue-violet color from trace amounts of vanadium. The gemstone is found in only one place on Earth: a tiny, four-square-kilometer mining area in the Merelani Hills of Tanzania. This extreme rarity of origin is a major factor in its value and appeal.
The formation of Tanzanite is believed to have occurred around 585 million years ago during a massive tectonic plate shift. This event heated and compressed the rocks, allowing mineral-rich fluids to alter the original zoisite crystals, imbuing them with their extraordinary color. The mining of Tanzanite is a localized and challenging process, further cementing its status as a rare and precious gem.
Gemological Properties
Understanding the physical and chemical properties of a gemstone is crucial for both gemologists and consumers. These properties determine a stone's durability, appearance, and value.
| Property | Turquoise | Tanzanite |
|---|---|---|
| Chemical Composition | Hydrous phosphate of copper and aluminum | Calcium aluminum hydroxyl-silicate (Zoisite variety) |
| Color | Opaque, blue to green, often with a brown or black matrix | Trichroic: blue, violet, and burgundy; typically a vivid violet-blue |
| Hardness (Mohs Scale) | 5 - 6 | 6.5 - 7 |
| Crystal System | Triclinic | Orthorhombic |
| Transparency | Opaque | Transparent to Translucent |
| Luster | Waxy to subvitreous | Vitreous (glass-like) |
Color, Clarity, and Cut
The value of Turquoise is primarily determined by its color and matrix. The most prized color is an even, intense "robin's egg" blue, free from greenish tints. The presence and pattern of the matrix can either enhance or detract from its value; for example, a uniform, attractive spiderweb matrix in Persian turquoise is highly desirable. As an opaque stone, turquoise is typically cut into cabochons or beads.
Tanzanite's value is directly linked to the intensity of its blue-violet color. The most valuable stones exhibit a deep, saturated violet-blue, often referred to as "indigo tanzanite." The gem is known for its strong trichroism, meaning it displays three different colors (blue, violet, and a reddish-burgundy) when viewed from different crystallographic directions. Gem cutters must skillfully orient the rough stone to showcase the most desirable face-up color. Clarity is also important; high-quality tanzanite is typically eye-clean.
Durability and Hardness
The difference in hardness between the two stones is significant. Tanzanite, with a Mohs hardness of 6.5 to 7, is more durable than Turquoise (5 to 6). This makes Tanzanite more suitable for rings and jewelry that may be exposed to daily wear, although it is still more delicate than stones like sapphire or diamond. Turquoise, being softer and sometimes porous (especially if untreated), is more susceptible to scratching, chipping, and chemical damage. Both stones require careful handling to maintain their beauty.
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, both Turquoise and Tanzanite are rich in symbolic meaning and are believed by many to possess metaphysical properties.
Turquoise: The Master Healer
For centuries, Turquoise has been regarded as a stone of healing, protection, and good fortune. It is often called the "master healer" in metaphysical circles. Its energy is believed to be calming and grounding, helping to align the chakras and promote spiritual attunement. Many wear turquoise jewelry to foster tranquility, honest communication, and emotional balance. Its protective lore continues to this day, with many believing it can shield the wearer from negative energy and physical harm. It is also associated with wisdom, serenity, and courage.
Tanzanite: The Stone of Transformation
As a more recent addition to the world of crystal healing, Tanzanite has quickly been attributed with powerful properties. It is widely considered a stone of transformation, spiritual awakening, and higher consciousness. Its striking color is said to resonate with the higher chakras, particularly the third eye and crown chakras, enhancing intuition and psychic abilities. Some modern sources suggest that tanzanite can inspire truth and authenticity, helping individuals to live more consciously. It is also believed to promote a calm, meditative state and to be a powerful tool for those seeking to overcome old patterns and embrace new beginnings.
Care and Cleaning
Proper care is essential to preserve the luster and integrity of any gemstone. Due to their differing hardness and chemical composition, Turquoise and Tanzanite require distinct maintenance routines.
Caring for Turquoise
Because of its relative softness and potential porosity, Turquoise requires gentle care. * Avoid Chemicals: The stone is sensitive to chemicals, including lotions, perfumes, hairspray, and even some soaps, which can cause discoloration or damage its surface. It should be the last thing you put on and the first thing you take off. * Cleaning: Clean turquoise jewelry only with warm water, a mild soap, and a very soft cloth. Do not use ultrasonic cleaners or steamers, as the vibrations and heat can crack the stone or damage any stabilizing treatments. * Storage: Store turquoise separately from other jewelry to prevent scratches. Keep it away from excessive heat or prolonged direct sunlight, which can cause the color to fade.
Caring for Tanzanite
Tanzanite is more durable than turquoise but still requires careful handling. * Avoid Sudden Temperature Changes: Tanzanite is known to be sensitive to thermal shock. Do not expose it to sudden, extreme temperature changes, as this can cause internal fractures. * Protect from Impact: While it has a decent hardness, its cleavage can make it susceptible to chipping if struck against a hard surface. It is advisable to remove tanzanite jewelry during physical activities. * Cleaning: The safest method for cleaning tanzanite is with warm water, a drop of mild detergent, and a soft brush. As with turquoise, avoid ultrasonic cleaners and steamers, which can damage the stone. Always rinse thoroughly and dry with a soft, lint-free cloth.
Conclusion
December's birthstones, Turquoise and Indigo Tanzanite, offer a captivating duality. Turquoise is a timeless classic, a stone of ancient earth and enduring lore, valued for its protective qualities and serene blue-green beauty. Tanzanite is its modern counterpart, a geological rarity born from a dramatic event, celebrated for its intense violet-blue color and its association with spiritual transformation. Together, they provide a rich and varied choice for those born in the final month of the year, embodying both a deep connection to history and a vibrant vision of the future. Whether one is drawn to the protective embrace of an ancient amulet or the transformative energy of a modern marvel, December's gems deliver profound beauty and significance.