The date of December 19th holds a unique distinction in the gemological calendar, being associated not with a single gemstone, but with a distinguished triad: tanzanite, turquoise, and zircon. These three stones, each a modern birthstone for the month of December, represent a confluence of rare geological phenomena, ancient history, and profound cultural symbolism. Unlike months with a singular traditional stone, December offers a palette of colors and properties, from the sky-blue of ancient turquoise to the deep violet-blue of tanzanite and the brilliant fire of zircon. This article delves into the rich tapestry of these gems, exploring their historical journey to becoming birthstones, their geological origins, their distinct gemological characteristics, and the metaphysical beliefs that have surrounded them for centuries. We will examine the evolution of birthstone lists, the specific allure of each stone, and the practical care required to preserve their beauty, providing a comprehensive guide for enthusiasts, collectors, and those born on this significant day.
The Historical Evolution of December's Birthstones
The concept of linking specific gemstones to birth months is a practice with ancient roots, though its modern form is a relatively recent development. The earliest known association of gems with significance appears in the Biblical Book of Exodus, which describes a breastplate worn by Aaron, adorned with twelve distinct gemstones representing the twelve tribes of Israel. However, these stones were linked to tribes and individuals in a broader sense, not to specific calendar months.
The formalization of birthstone lists began to take shape in the 19th century. A pivotal moment occurred in 1870 when the renowned jewelry firm Tiffany & Co. published the first American version of a birthstone list. This initial list designated turquoise as the birthstone for the month of December, establishing a foundational association that persists to this day. The tradition was further solidified in 1912 when the National Association of Jewellers (now the American Gem Trade Association) convened to create a standardized list. This list not only confirmed turquoise but also expanded the options by including lapis lazuli as an alternative.
The following decades saw further additions to the December roster. In 1952, zircon was officially added to the list, introducing a gem known for its exceptional brilliance and fire. The most recent major addition came in 2002, when tanzanite was included as a third modern birthstone for December. This decision reflected the gem's rising popularity and its unique, captivating color. The inclusion of multiple stones for December is intentional, offering individuals born in this month a wider array of choices in terms of color, price point, and personal significance. For those born on December 19th, this triad of gems provides a particularly rich heritage, each stone carrying its own unique story and set of attributes.
Tanzanite: A Modern Marvel of Violet-Blue
Tanzanite is the youngest of the modern birthstones, a gem whose history is measured in decades rather than millennia. Its story began in 1967, when it was discovered by a prospector named Manuel de Souza near the base of Mount Kilimanjaro in the Merelani Hills of Tanzania. Initially found as a brownish-violet rock, the stone's true potential was soon realized. Through a process of heat treatment, the rough material was transformed, revealing the intense and vibrant blue to violet hues that the gem is now famous for. This heat treatment is a standard practice and is stable, permanently setting the gem's desirable color.
Geologically, tanzanite is a variety of the mineral zoisite. Its occurrence is incredibly localized, found in only one small area of the world, which contributes to its rarity and value. This single-source origin makes it a truly unique gemstone in the mineral kingdom. The gem's color, often described as "velvety" and "sensual," ranges from a pure ultramarine blue to a vibrant violet, with the most prized stones exhibiting a rich blue color with pleochroic flashes of violet and red. The gemological community often refers to its color as "blue-violet," a distinct shade that has no direct parallel among other gemstones. Its discovery and rapid rise to prominence have made it a symbol of modern gemology, a testament to how new and significant gem sources can still be found in the modern era.
Turquoise: An Ancient Stone of Protection and Wisdom
In stark contrast to the youthful tanzanite, turquoise is one of the oldest known gemstones, with a history of human use and admiration that spans thousands of years. Its name is derived from the French "pierre turquoise," meaning "Turkish stone," as the gem was first brought to Europe from Turkey via the Persian trade routes. However, its use long predates this nomenclature. Ancient civilizations, including the Egyptians, Persians, and Native Americans, held turquoise in the highest esteem.
Turquoise is a phosphate mineral of copper and aluminum, which gives it its characteristic blue to blue-green color. The presence of copper results in the sky-blue hues, while traces of iron can produce a greenish tint. The gem is typically found in arid regions as a secondary mineral in areas where water has percolated through rocks containing aluminum and copper minerals. Major sources include Iran (historically the most significant), the Southwestern United States (Arizona, New Mexico, Nevada), and parts of China.
Beyond its physical beauty, turquoise has been imbued with immense cultural and symbolic meaning. For centuries, it has been regarded as a stone of protection, believed to safeguard the wearer from harm and bring good fortune. Ancient warriors would inlay it into their shields and armor, while it was also used to create intricate mosaics and ceremonial objects. In many cultures, it is associated with wisdom, tranquility, and communication. Its connection to the sky and water element reinforces these themes of calm and clarity. As the traditional birthstone for December, turquoise carries the weight of this ancient legacy, offering a link to a deep and storied past.
Zircon: The Fiery Gem of Ancient Origins
Zircon is a gem often misunderstood due to its name's similarity to "cubic zirconia," a synthetic diamond simulant. However, natural zircon is one of the oldest minerals on Earth, with zircon crystals found in Australian sediments dating back over 4.4 billion years, making them the oldest known material on the planet. This ancient lineage lends the gem an air of primordial significance.
Zircon is a silicate of zirconium, and it occurs in a variety of colors. The most prized and well-known variety is the blue zircon, which has become a popular December birthstone. Like tanzanite, the vibrant blue color of most zircon on the market is the result of a heat treatment process applied to brownish zircon crystals. Untreated zircon can be found in a range of colors, including colorless, yellow, orange, and red (the latter being exceptionally rare and valuable). The gem's most notable physical characteristic, aside from its hardness, is its exceptional brilliance and fire, which rival that of diamond. This high refractive index and strong dispersion give cut zircon a dazzling sparkle that makes it a standout in jewelry.
Historically, colorless zircon was used as a diamond substitute in centuries past, and its brilliance was highly valued. Blue zircon, in particular, gained popularity during the Victorian era in England, where it was often used in intricate jewelry designs. As a birthstone, zircon is associated with wisdom, wealth, and honor. Its ancient nature and brilliant optical properties make it a compelling choice for those born in December, representing both a connection to the deep past and a vibrant, sparkling present.
Gemological Properties: A Comparative Analysis
Understanding the physical and chemical properties of these three gemstones is crucial for appreciating their unique characteristics and for their proper care. Each stone presents a distinct profile in terms of hardness, stability, and optical properties. The following table summarizes the key gemological data for tanzanite, turquoise, and zircon, based on established information.
| Property | Tanzanite | Turquoise | Zircon |
|---|---|---|---|
| Mineral Species | Zoisite | Hydrated phosphate of copper and aluminum | Zirconium Silicate |
| Chemical Formula | Ca₂Al₃(SiO₄)₃(OH) | CuAl₆(PO₄)₄(OH)₈·4H₂O | ZrSiO₄ |
| Hardness (Mohs Scale) | 6.5 - 7 | 5 - 6 | 6.5 - 7.5 |
| Crystal System | Orthorhombic | Triclinic | Tetragonal |
| Refractive Index | 1.691 - 1.700 | 1.610 - 1.650 | 1.920 - 2.010 |
| Color | Blue to violet | Sky-blue to greenish-blue | Colorless, blue, yellow, brown, red |
| Durability | Fairly good, but can be brittle; prone to chipping if knocked. | Soft and porous; susceptible to scratching, chemicals, and heat. | Good to excellent, but can be brittle; high refractive index. |
From this data, we can observe significant differences. Turquoise, with a Mohs hardness of only 5 to 6, is the softest and most porous of the three, making it the most vulnerable to damage and chemical exposure. Tanzanite and zircon are slightly harder, but both can be brittle. Zircon's high refractive index is what gives it its exceptional brilliance, while tanzanite's pleochroism (displaying different colors when viewed from different angles) is one of its most fascinating properties.
Symbolism and Metaphysical Beliefs Across Cultures
Beyond their physical attributes, these three gemstones are steeped in a rich history of symbolism and metaphysical beliefs. These associations, passed down through generations, add a layer of intangible value to the gems.
Turquoise is perhaps the most potent in this regard. It is widely regarded as a master healing stone, believed to align and balance all the chakras, particularly the Throat and Heart Chakras, fostering clear communication and compassionate expression. Its protective qualities are legendary; it is said to warn the wearer of danger or misfortune by changing color. Many Native American cultures view it as a sacred stone, a conduit to the sky world and a bringer of peace and good fortune.
Tanzanite, being a newcomer, has developed its own set of modern metaphysical associations. It is often linked to spiritual awakening and higher consciousness. Its calming, soothing energy is believed to alleviate stress, anxiety, and feelings of being overwhelmed. Practitioners suggest that tanzanite can help one develop their intuition and psychic abilities, making it a stone for those on a path of spiritual growth and transformation.
Zircon is associated with honor, purity, and wisdom. It is believed to help with sleep, warding off nightmares and promoting restful nights. In the realm of prosperity, zircon is thought to attract wealth and abundance. It is also linked to the energy of new beginnings and is often used as a talisman for travelers, ensuring a safe and prosperous journey. Its brilliant light is seen as a metaphor for clarity of thought and purpose.
Care and Maintenance of December's Gems
Given their differing physical properties, the care and cleaning of tanzanite, turquoise, and zircon require distinct approaches. Proper maintenance is essential to ensure the longevity and beauty of these stones, especially when set in jewelry.
Turquoise Care: Due to its porosity and relative softness, turquoise requires the most careful handling. - Cleaning: It should only be cleaned with warm water, a mild soap, and a soft cloth or a soft-bristled brush. Ultrasonic and steam cleaners are strictly forbidden as they can damage the stone. Harsh chemicals, including cosmetics, perfumes, and even skin oils, can discolor turquoise over time. It is advisable to put on turquoise jewelry last when dressing and to remove it before swimming or bathing. - Storage: Store turquoise separately from other, harder gemstones to prevent scratches. A soft pouch or a compartmentalized jewelry box is ideal.
Tanzanite Care: Tanzanite's hardness of 6.5-7 is respectable, but its brittleness means it can be chipped or cracked by a sharp blow. - Cleaning: Like turquoise, it is best cleaned with warm, soapy water and a soft brush. Avoid harsh chemicals and sudden temperature changes. While it is generally stable to heat, it is always best to err on the side of caution. - Storage: Store tanzanite jewelry in a soft cloth or a padded jewelry box, away from other stones that could scratch it or cause impact damage. Due to its cleavage (a tendency to break along flat planes), it is particularly vulnerable to sharp blows.
Zircon Care: Zircon is relatively durable but can be brittle. - Cleaning: It is generally safe to clean with warm, soapy water and a soft brush. It can withstand mild heat, but caution is advised with extreme temperature changes. Ultrasonic cleaning is usually safe for stones without significant inclusions, but steam cleaning should be avoided. - Storage: To prevent scratches, store zircon separately from other gems. Its hardness is similar to tanzanite, so it should be handled with care to avoid impacts that could cause chipping.
For those fortunate enough to own jewelry featuring these December 19th birthstones, following these care guidelines will ensure that the gems remain vibrant and meaningful for generations.
Conclusion
The gemstones associated with December 19th—tanzanite, turquoise, and zircon—offer a remarkable study in diversity, history, and beauty. Together, they form a trio that spans the breadth of human experience with gemstones, from the ancient, earthy wisdom of turquoise to the modern, spiritual allure of tanzanite and the timeless, brilliant fire of zircon. Their journey from ancient talismans and royal adornments to modern birthstones reflects a continuous human fascination with the colors and energies locked within the Earth. For the individual born on this day, these stones provide not only a beautiful palette of blues and violets but also a rich heritage of cultural symbolism and metaphysical properties. By understanding their origins, appreciating their unique gemological characteristics, and knowing how to care for them, one can forge a deeper connection with these extraordinary gems, ensuring their legacy and beauty endure.