December is unique in the world of birthstones, distinguished by its assignment of three distinct and visually captivating gemstones. While many months claim a single stone, December offers a palette of blues ranging from the soft, opaque sky of Turquoise to the vibrant violet-blue of Tanzanite and the brilliant, clear sparkle of Zircon. This variety provides those born in the final month of the year a wealth of choice, each stone carrying its own rich history, geological story, and symbolic weight. Recognized as the official birthstones for December, Turquoise, Tanzanite, and Zircon collectively represent themes of wisdom, protection, and spiritual growth, making them enduringly popular in jewelry and lore.
The primary birthstone for December is Turquoise, a gem revered for millennia for its distinctive color and protective qualities. Tanzanite, a relatively modern discovery, has rapidly ascended to become a celebrated symbol of transformation and new beginnings. Rounding out the trio is Zircon, one of the oldest known minerals on Earth, prized for its exceptional brilliance and historical association with prosperity. This article will provide a comprehensive exploration of these three remarkable gemstones, delving into their geological origins, gemological properties, historical significance, and the cultural beliefs that have elevated them to their esteemed status.
History and Lore
The history of December's birthstones is a fascinating journey through time, encompassing ancient civilizations, royal treasures, and modern discoveries. Each stone carries a legacy that contributes to its contemporary significance.
Turquoise: An Ancient Talisman
Turquoise is arguably one of the oldest known gemstones, with a history stretching back thousands of years. Its name provides a clue to its journey into Western culture; "Turquoise" is derived from the French phrase pierre turquoise, meaning "stone of Turkey." This nomenclature arose because the gem was first brought to Europe from Turkish bazaars. The stone was known and prized long before this, however. Ancient cultures across the globe recognized its power and beauty. It adorned the burial masks of Egyptian pharaohs and was a favored material in the jewelry of ancient Persian and Native American civilizations.
The stone’s significance extended beyond mere adornment. It was widely regarded as a powerful protective talisman, believed to ward off negative forces and bring good fortune to the wearer. Its distinctive color, ranging from powdered blue to a greenish robin's-egg blue, was so iconic that it gave its name to the color itself. The most prized variety, historically, was the sky-blue turquoise found in ancient Persia (modern-day Iran), a color now commonly referred to as "Persian blue." Over time, the Sinai Peninsula in Egypt also became a major source. Today, the United States is recognized as the world's largest provider of turquoise, continuing a long tradition of mining this beloved stone.
Tanzanite: The Jewel of a Generation
In stark contrast to the ancient lineage of Turquoise, Tanzanite is a newcomer to the gemological world. This stunning gem was discovered in 1967 in the Merelani Hills of northern Tanzania, near the majestic Mount Kilimanjaro. Its discovery is a modern gemstone story, and its name is a direct homage to its country of origin. Tanzanite is a variety of the mineral zoisite and is celebrated for its remarkable trichroism, a optical property that allows it to appear in different colors—blue, purple, and burgundy—depending on the viewing angle.
Due to its origin in a single, limited location on the planet, tanzanite is considered one of the rarest gemstones in the world. This extreme rarity, combined with its captivating beauty, has fueled its rapid rise in popularity. It was officially added to the list of modern birthstones in 2002, making it the most recent addition to the traditional birthstone list. Its symbolism is deeply connected to its modernity and unique properties; it is associated with transformation, spiritual awareness, and new beginnings, reflecting its own "birth" into the gemstone market.
Zircon: The Oldest Mineral with a Sparkling Legacy
Zircon is a gemstone with a dual identity. It is both one of the oldest minerals on Earth—some zircon crystals date back billions of years—and a source of brilliant sparkle that rivals diamond. For December, the gem is specifically associated with its blue variety. The name "zircon" is likely derived from the Persian word zargun, meaning "gold-colored," though it is most famous today for its colorless and blue forms.
Historically, zircon was associated with prosperity and success. It has been used in jewelry for centuries, and its high refractive index and strong luster give it a fiery brilliance that has long been admired. While zircon occurs in a rainbow of colors, including yellow, red, and green, the blue variety is the one traditionally linked to December. Its enduring presence in the geological record and its long history in human adornment make it a bridge between the ancient earth and the art of jewelry.
Geological Formation and Sources
Understanding how these gemstones are formed and where they are found provides deeper insight into their unique characteristics and value.
Turquoise: A Product of Water and Earth
Turquoise is not formed by the intense heat and pressure that create many other gemstones. Instead, it is a secondary mineral formed by the percolation of water through rock. The process begins when groundwater, rich in copper and aluminum, seeps into the bedrock. Over long periods, this copper-bearing solution reacts with minerals containing phosphorus and aluminum, slowly depositing turquoise in the cracks and voids of the rock. This formation process explains why turquoise is almost always opaque and often contains a matrix—dark lines or web-like patterns of the host rock (such as chalcedony or ironstone) that become part of the gem itself.
The world's major turquoise sources include: * Iran (Persia): Historically the source of the finest "Persian blue" turquoise. * The United States: The world's largest current provider, with significant deposits in states like Arizona, Nevada, and New Mexico. * Tibet: A source of turquoise with a distinct history and color. * India: Another notable region for turquoise mining.
Tanzanite: A Geological Rarity
Tanzanite's existence is the result of a unique geological event. It is found in only one place on Earth: a tiny, four-square-kilometer area near Mount Kilimanjaro in Tanzania. The formation of tanzanite is linked to the tectonic upheaval that created the Great Rift Valley. Heat and chemical alteration of the parent rock, zoisite, by nearby metamorphic processes created the conditions for tanzanite to form. Its extreme rarity is a direct consequence of this singular geological event; the specific combination of elements and conditions required for its creation has not been replicated elsewhere.
Zircon: A Primary Mineral Crystallized from Magma
Unlike turquoise, zircon is a primary mineral, meaning it crystallizes directly from molten rock (magma). It is one of the first minerals to form as magma cools, making it extremely durable and resistant to weathering. This durability allows ancient zircon crystals to survive in sedimentary deposits, providing a record of the Earth's earliest history.
For December birthstone jewelry, the blue variety of zircon is most common. This blue color is typically achieved through heat treatment of brownish zircon crystals. Major sources for zircon include: * Cambodia * Sri Lanka * Thailand * Australia
Gemological Properties
The distinct nature of each of December's birthstones is clearly defined by their unique gemological characteristics. These properties determine not only their appearance and durability but also how they are cut, worn, and cared for.
The following table summarizes the key physical properties of Tanzanite, Turquoise, and Zircon, based on data from gemological sources:
| Property | Tanzanite | Turquoise | Zircon |
|---|---|---|---|
| Mineral | Zoisite (Ca₂Al₃(SiO₄)₃(OH)) | Hydrated copper aluminum phosphate | Zirconium silicate (ZrSiO₄) |
| Color | Blue to violet-blue, purple | Blue to green-blue | Blue (for December), also colorless, yellow, red, green |
| Hardness (Mohs) | 6 - 7 | 5 - 6 | 7.5 |
| Transparency | Transparent to translucent | Opaque | Transparent to translucent |
| Refractive Index | 1.691 - 1.700 | 1.61 - 1.65 | 1.925 - 1.984 |
| Crystal System | Orthorhombic | Triclinic | Tetragonal |
| Specific Gravity | 3.35 | 2.6 - 2.8 | 3.90 - 4.73 |
Color and Appearance
- Turquoise: Prized for its unique opaque, waxy appearance and its color range from soft sky blue to greenish-blue. The presence of the matrix, the host rock remnants, creates distinctive patterns that are often considered a mark of authenticity and beauty.
- Tanzanite: Its most captivating feature is its trichroism, which displays a mesmerizing play of blue and violet hues. The most sought-after color is a deep, rich violet-blue.
- Zircon: Known for its exceptional brilliance and fire, which is often compared to that of a diamond. The blue variety can range from a light, airy blue to a deeper, more saturated tone.
Hardness and Durability
Hardness, measured on the Mohs scale, is a critical factor for jewelry. It indicates a gem's ability to resist scratching.
- Zircon (7.5): With a hardness of 7.5, zircon is quite durable and suitable for all types of jewelry, including rings, though care should be taken to avoid hard blows as it can be brittle.
- Tanzanite (6-7): Tanzanite's hardness of 6-7 makes it moderately durable. However, due to its perfect cleavage in one direction, it is susceptible to chipping or breaking if struck with force. It is best set in protective settings like bezels, especially for rings or bracelets.
- Turquoise (5-6): As the softest of the trio, turquoise is more delicate. It is prone to scratching and can be damaged by chemicals, lotions, and even the oils from skin contact, which can alter its color over time. It is best suited for earrings, pendants, and occasional-wear rings.
Symbolism and Metaphysical Beliefs
Across cultures and centuries, these three gemstones have been imbued with powerful symbolic meanings and metaphysical properties, which continue to resonate with many today.
Universal Themes of Wisdom and Protection
The blue trio of December shares some overarching symbolic themes. All three stones are associated with wisdom, believed to enhance mental clarity, focus, and clear decision-making. They are also linked to spiritual growth and healing, serving as tools for introspection and connection to higher consciousness.
Unique Symbolic Attributes
- Turquoise: The ultimate protective talisman. It has been worn for centuries to ward off negative energy and bring good fortune, success, and happiness. It is also thought to enhance communication skills, allowing the wearer to speak their truth with clarity and confidence.
- Tanzanite: A stone of transformation. Its discovery in the modern era and its unique color-shifting properties make it a powerful symbol for those undergoing significant life changes, representing new beginnings and spiritual awakening.
- Zircon: A gem of clarity and balance. Historically, it has been associated with prosperity and success. It is believed to help its wearer achieve a sense of balance in life, promoting confidence and a deeper understanding of oneself.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of any gemstone. Due to their differing properties, each of December's birthstones requires a specific care regimen.
- Turquoise: This is the most delicate of the three. It should be cleaned with warm water, a mild soap, and a very soft cloth. Avoid ultrasonic cleaners, steam cleaners, and harsh chemicals, as these can damage the stone. Store turquoise jewelry separately to prevent it from being scratched by harder gems.
- Tanzanite: Clean tanzanite with warm, soapy water and a soft brush. It is crucial to avoid ultrasonic cleaners and steam cleaners, as the heat and vibrations can cause the stone to fracture due to its perfect cleavage. Given its relative softness and fragility, it should be handled with care and stored in a soft pouch.
- Zircon: Despite its hardness, zircon can be brittle. Clean it with warm, soapy water and a soft brush. It is generally safe for ultrasonic cleaning, but caution is advised if the stone has been subjected to heat treatment or has inclusions. Steam cleaning is not recommended.
Conclusion
December's birthstones—Turquoise, Tanzanite, and Zircon—offer a remarkable trifecta of beauty, history, and symbolism. From the ancient protective powers of Turquoise, with its earthy, opaque charm, to the transformative, vibrant energy of the rare Tanzanite, and the brilliant, wisdom-imbued sparkle of Zircon, each gem provides a unique expression for those born in the final month of the year. Their diverse origins, distinct gemological properties, and rich cultural legacies ensure that they remain not only cherished birthstones but also enduring favorites in the world of fine jewelry. Whether chosen for their color, durability, or the meaning they hold, these three blue gems provide a wealth of options that are as timeless as they are captivating.