For those born in the final month of the year, the gift of birthstones is not a singular choice but a vibrant trinity of gems, each possessing a distinct character, history, and geological origin. December is uniquely adorned with three primary birthstones: the ancient and earthy Turquoise, the brilliantly fiery Zircon, and the modern, velvety Tanzanite. This exceptional variety offers a spectrum of colors, from the sky-blue of Turquoise to the multifaceted brilliance of Zircon and the captivating blue-violet of Tanzanite. This guide delves into the rich tapestry of information surrounding these three remarkable gemstones, exploring their geological formation, storied pasts, unique gemological properties, and the symbolic meanings that have captivated humanity for millennia.
History and Lore
The historical narratives of December's birthstones span from the ancient world to the modern day, each stone carrying a legacy steeped in cultural significance and belief.
Turquoise As one of the oldest known gemstones, Turquoise boasts a history that stretches back thousands of years. It was a cherished gem in ancient Egypt, where it was unearthed from the tombs of Pharaohs. In this context, Turquoise symbolized eternal life and was believed to have the power to ward off evil spirits. Its significance transcended mere ornamentation, serving as a powerful amulet for protection in the afterlife. Beyond Egypt, Turquoise held a vital place in Native American culture, where it was not only a ceremonial gem but also served as a medium of exchange. This ancient reverence establishes Turquoise as a stone deeply connected to spiritual beliefs and ceremonial practices across diverse civilizations.
Zircon Zircon possesses a history that is, in a geological sense, almost as old as the Earth itself, with an age spanning over 4.4 billion years, making it one of the planet's oldest minerals. This ancient origin gives Zircon a unique place among gemstones. Historically, colorless Zircon was often mistaken for diamond due to its high brilliance and fire, a confusion that persists in modern times with the unrelated synthetic material, cubic zirconia. Blue Zircon, in particular, has been a notable variety, though its identity has sometimes been conflated with other blue stones. Despite this, its stunning optical properties have made it a prized gem throughout history, particularly in its colorless and blue forms.
Tanzanite In stark contrast to the ancient lineage of Turquoise and Zircon, Tanzanite is a distinctly modern gem with a very specific and recent origin story. It was first discovered in the mid-20th century and is found in only one location on Earth: the Merelani Hills of Northern Tanzania. Its discovery was relatively recent, which accounts for its absence from ancient lore. However, it quickly gained international fame for its unique and alluring color, a velvety blue-violet hue unlike any other gemstone. As a new addition to the world of colored stones, its history is still being written, defined by its rarity and its rapid ascent to prominence in the jewelry market.
Geological Formation and Sources
Understanding the origins of these gemstones reveals the diverse geological processes that create them and highlights their unique geographic footprints.
Turquoise Turquoise is an aggregate mineral, chemically described as a copper aluminum phosphate. Its formation is a specific geological event that occurs in arid regions. It is created when acidic, copper-rich water percolates through deposits of copper ore, known as copper porphyry. This water interacts with aluminum and potassium in the surrounding rocks, causing the turquoise to precipitate and fill cavities within weathered volcanic and sedimentary rock. Consequently, major sources for this gem are found in arid locations across the globe. Historically significant mines are located in Iran (formerly Persia), which is famed for its "Persian blue" or "robin's egg blue" turquoise. Other notable sources include the southwestern United States and Mexico.
Zircon Zircon is a zirconium silicate mineral that forms within igneous and metamorphic rocks. While it is one of the oldest minerals on Earth, gem-quality Zircon is sourced from various modern locations. The provided materials indicate that Blue Zircon, the most popular color variety for jewelry, has deposits found in numerous locations around the world. The most significant sources for gem-quality zircon include Cambodia, Sri Lanka, and Thailand. Its widespread distribution means it is available from multiple continents, contributing to its accessibility as a birthstone choice.
Tanzanite The geological story of Tanzanite is one of extreme rarity. It is a variety of the mineral zoisite and is found exclusively in a very small mining area in the Merelani Hills of Northern Tanzania. This single-source origin makes Tanzanite hundreds of times rarer than diamond. Its formation is linked to a unique geological event that occurred over 500 million years ago, when intense heat and pressure altered the zoisite crystals, imbuing them with their characteristic blue-violet color. The limited geographic scope of its occurrence is a primary factor in its value and allure.
Gemological Properties
Each of December's birthstones has a distinct set of physical and chemical properties that define its durability, appearance, and care requirements.
| Gemstone | Chemical Composition | Hardness (Mohs Scale) | Crystal System | Key Properties |
|---|---|---|---|---|
| Turquoise | Copper Aluminum Phosphate | 5 - 6 | Triclinic | Opaque, porous, prone to discoloration from oils and chemicals. |
| Zircon | Zirconium Silicate | 6.5 - 7.5 | Tetragonal | High brilliance and fire; can be brittle due to cleavage. |
| Tanzanite | Calcium Aluminum Silicate (Zoisite) | 6.5 - 7 | Orthorhombic | Trichroic (displays three different colors); often heat-treated. |
Turquoise Turquoise is an opaque gem with a hardness of 5 to 6 on the Mohs scale, making it a relatively soft stone. This low hardness means it can be scratched or broken with moderate force. Its structure is also porous, which makes it susceptible to absorbing oils, pigments, and chemicals, leading to discoloration. For this reason, turquoise used in jewelry is often stabilized or treated to improve its durability and color retention. Its color ranges from sky blue to greenish-blue, depending on the amount of copper and iron present during its formation.
Zircon Zircon is a much harder and more durable gemstone, with a hardness ranging from 6.5 to 7.5 on the Mohs scale. This makes it suitable for a variety of jewelry applications, including rings. It is renowned for its exceptional brilliance and fire, which rival that of diamond. However, despite its hardness, Zircon can be brittle due to its perfect cleavage in two directions, meaning it can be chipped by sharp impacts. It is available in a range of colors, including colorless, yellow-gold, and the popular blue variety.
Tanzanite Tanzanite has a hardness of 6.5 to 7 on the Mohs scale, making it moderately durable. Its most remarkable gemological characteristic is its trichroism—the ability to display three different colors when viewed from three different crystallographic directions: blue, violet, and a reddish hue. The gem's signature blue-violet color is the result of heat treatment applied to brownish zoisite crystals, a standard industry practice that enhances the stone's value and appeal. Due to its clarity and color, it is a popular choice for faceted gems in pendants, earrings, and rings.
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, these gemstones are rich in symbolism and are believed by many to possess metaphysical properties.
Turquoise: Associated with the sky and water, Turquoise is widely believed to symbolize life, joy, and abundance. It is considered a protective stone, traditionally used to ward off negative energy and bring good fortune. In metaphysical practices, it is often linked to the Throat Chakra, supporting clear communication and honest expression. Some modern sources also attribute physical benefits to it, such as aiding digestion and supporting the immune system.
Zircon: This ancient stone is believed to enhance wisdom, knowledge, and spiritual growth. It is also associated with prosperity and is thought to attract wealth. For those seeking rest and tranquility, Zircon is said to promote restful sleep and ward off nightmares. Its clarity and brilliance are symbolic of purity and focus.
Tanzanite: As a relatively new stone, its metaphysical lore is modern but powerful. It is known as a stone of transformation and is believed to foster compassion, calmness, and a higher consciousness. Physically, some sources suggest Tanzanite can improve skin and hair health. It is often associated with the higher chakras, facilitating a connection to one's spiritual guides.
Care and Cleaning
The durability of each stone dictates the proper methods for its care and maintenance.
Turquoise: Due to its softness and porosity, Turquoise requires gentle care. It should be cleaned with warm, soapy water and a soft cloth. It is crucial to avoid ultrasonic cleaners, steam cleaners, and any chemicals, including cosmetics and perfumes, which can damage or discolor the stone. Store it separately to prevent scratching by harder gems.
Zircon: Although harder, Zircon's brittleness means it should be protected from sharp blows. It is susceptible to damage along its cleavage planes. Cleaning can be done with warm, soapy water and a soft brush. Avoid sudden temperature changes, as some zircon (especially blue varieties) can be sensitive to heat.
Tanzanite: With a hardness of 6.5 to 7, Tanzanite is moderately durable but should still be handled with care. It is not recommended for daily-wear rings that are exposed to hard knocks. Cleaning is best done with warm, soapy water and a soft brush. As with other delicate gems, avoid ultrasonic and steam cleaners, which can cause damage.
Conclusion
December's birthstones offer a remarkable diversity that is unmatched by any other month. From the ancient, protective talisman of Turquoise to the earth's oldest mineral, Zircon, and the rare, modern marvel of Tanzanite, each stone provides a unique connection to the natural world. Their distinct histories, from the tombs of Egyptian pharaohs to the mines of Tanzania, and their varied physical properties make them a fascinating subject for gemstone enthusiasts and a meaningful choice for jewelry buyers. This triad of gems ensures that anyone born in December can select a birthstone that perfectly reflects their personal style and appreciation for geological wonders, historical depth, and enduring beauty.