Individuals born in December are uniquely fortunate, as they can claim not one, but four distinct gemstones as their own. Unlike months with a singular birthstone, December offers a quartet of blue-hued treasures: Turquoise, Zircon, Tanzanite, and Blue Topaz. Each of these gems possesses a unique geological origin, a rich history, and specific gemological properties that set them apart. From the ancient, opaque wisdom of Turquoise to the rare, violet-blue brilliance of Tanzanite, these stones capture the essence of winter’s cool palette. This guide explores the origins, characteristics, symbolism, and care requirements of each of December’s four birthstones, providing a detailed resource for gemstone enthusiasts, collectors, and jewelry buyers.
Turquoise: The Ancient Guardian
Turquoise stands as the oldest and most traditional of December’s birthstones, a gem cherished for millennia across diverse cultures. Its name is derived from the French phrase pierre tourques, or "Turkish stone," reflecting the trade routes that brought the gem from Persian mines to Europe through Turkey.
History and Lore
The historical significance of Turquoise is vast. It has been discovered adorning Egyptian pharaohs and was a favorite of King Tutankhamun. In ancient Persia, it was worn as a protective amulet against unnatural death, with the belief that its color would change to warn the wearer of impending danger. Similarly, Native American cultures have long revered the stone, associating it with the sky and water and incorporating it into sacred ceremonies and jewelry. Historically, it was believed to protect the wearer from falls and negative energy. Today, it symbolizes wisdom, tranquility, and friendship.
Geological Formation and Sources
Turquoise is a phosphate mineral that forms in arid regions where acidic, copper-rich groundwater percolates through aluminum-bearing rocks. This process creates veins and nodules, often resulting in a "matrix" appearance where the host rock remains intertwined with the turquoise. The most significant sources include the southwestern United States (Arizona, New Mexico, Nevada), Iran, Egypt, China, Mexico, and parts of Central Asia and Africa.
Among these, Persian turquoise from Iran is considered the most prized variety. It is celebrated for its vivid, evenly saturated sky-blue color and characteristically minimal to nonexistent matrix. Another highly valued variety is Sleeping Beauty Turquoise, known for its pure, robin's-egg blue color. This stone was mined exclusively from the Sleeping Beauty Mine in Arizona before its closure.
Gemological Properties
Turquoise is typically an opaque gemstone, ranging in color from sky blue to green. Its appearance can vary significantly based on its composition and the presence of the host rock matrix.
- Hardness: Turquoise ranks between 5 and 6 on the Mohs hardness scale. This makes it a relatively soft gemstone that requires careful handling to avoid scratches and damage.
- Composition: It is a hydrated phosphate of copper and aluminum.
- Clarity/Transparency: It can be semi-transparent but is most often opaque.
Symbolism and Metaphysical Beliefs
Beyond its protective history, Turquoise is widely regarded as a master healing stone. It is associated with the throat chakra, promoting clear communication and self-expression. Metaphysically, it is believed to imbue the wearer with inner calm and peace, making it a popular stone for meditation and spiritual grounding.
Care and Cleaning
Due to its porosity and relative softness, Turquoise requires specific care. It is sensitive to chemicals, including cosmetics, skin oils, and even some soaps, which can cause discoloration. It should be cleaned with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaning. To maintain its color and integrity, it is best to store turquoise jewelry separately from harder stones.
Zircon: The Diamond Impostor
Blue Zircon is one of the traditional December birthstones, often confused with the synthetic cubic zirconia, though the two are entirely different minerals. Natural Zircon is one of the oldest minerals on Earth, providing a link to the planet's early geological history.
History and Lore
Zircon has been used in jewelry for centuries. During the Middle Ages, it was believed to bring wisdom, honor, and prosperity to its wearer. It was also thought to induce sleep and ward off evil spirits. The confusion between zircon and cubic zirconia has unfortunately diminished its profile in the modern market, but fine blue zircon remains a highly sought-after gem by connoisseurs.
Geological Formation and Sources
Zircon is a zirconium silicate mineral that forms in igneous and metamorphic rocks. The blue variety used in jewelry is almost always heat-treated to achieve its desirable color. The process involves heating brown zircon to very high temperatures, which changes its crystal structure and color. Major sources of Zircon include Cambodia, Sri Lanka, and Thailand.
Gemological Properties
Blue Zircon is renowned for its exceptional brilliance and fire, which can rival that of a diamond. Its high refractive index and strong dispersion contribute to its dazzling appearance.
- Hardness: Zircon has a hardness of 7.5 on the Mohs scale, making it a durable choice for jewelry, though it is more brittle than a diamond due to its perfect cleavage.
- Composition: Zirconium silicate (ZrSiO₄).
- Refractive Index: High (1.92-1.98), contributing to its brilliance.
- Specific Gravity: 4.6-4.7.
Symbolism and Metaphysical Beliefs
Zircon is associated with honor, purity, and spiritual grounding. It is believed to help its wearer achieve wisdom and wealth while promoting a sound sleep and peaceful dreams. The blue variety is particularly linked to clarity of thought and calmness.
Care and Cleaning
Zircon is relatively durable but has perfect cleavage in two directions, meaning it can fracture if struck with force. It should be protected from sharp blows. Cleaning can be done with warm, soapy water and a soft brush. Ultrasonic and steam cleaning are generally not recommended due to the risk of fracture.
Tanzanite: The Violet Sensation
Tanzanite is the most recent addition to the December birthstone family, yet it has quickly become one of the most popular and valuable gems on the market. Its singular origin and striking color make it a true gemological phenomenon.
History and Lore
Tanzanite was first discovered in the 1960s in the Merelani Hills of northern Tanzania. Its popularity was catapulted by the jewelry company Tiffany & Co., which recognized its beauty and began marketing it heavily in 1968, naming it after its country of origin. Due to its recent discovery, Tanzanite lacks the ancient lore of Turquoise or Zircon, but it has quickly developed its own symbolism, often associated with transformation and modern elegance.
Geological Formation and Sources
Tanzanite is a variety of the mineral zoisite. Its formation is exceptionally rare, occurring in only one small area of the world. It is found in the Merelani Hills of Tanzania, at the foot of Mount Kilimanjaro. Geologists believe that a unique combination of geological events—specifically, the tectonic shift of the African and Somali plates and the subsequent metamorphism of the host rock—created the conditions necessary for zoisite to form with the specific trace elements that give it its signature blue-violet color.
Gemological Properties
Tanzanite is celebrated for its pleochroism, the ability to display different colors when viewed from different crystallographic directions. It typically appears blue in one direction and violet in another.
- Hardness: It ranks between 6.5 and 7 on the Mohs scale, making it suitable for jewelry but requiring some care.
- Composition: Calcium aluminum hydroxyl sorosilicate.
- Color: The most desirable color is a deep, saturated violet-blue. Most tanzanite is heat-treated to remove brownish hues and enhance the blue and violet tones.
- Pleochroism: Strongly trichroic (showing three colors: blue, violet, and red-brown).
Symbolism and Metaphysical Beliefs
As a relatively new gem, Tanzanite is often linked to a "new age" of spirituality. It is said to facilitate a higher consciousness, intuition, and spiritual perception. It is also associated with compassion and a unique "zen-like" calm.
Care and Cleaning
Tanzanite is more delicate than Zircon or Blue Topaz. It has poor toughness and is susceptible to chipping and abrasion. It is not recommended for rings worn daily, such as engagement rings, unless set in a protective mounting. Cleaning should be done with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaning, as the heat and vibrations can cause damage.
Blue Topaz: The Modern Classic
Blue Topaz is the most durable of the December birthstones and has become a modern staple in jewelry due to its brilliant color and affordability. While natural blue topaz is rare, the vast majority of blue topaz on the market is the result of treating colorless topaz.
History and Lore
The name "topaz" is believed to derive from the Sanskrit word tapas, meaning "fire." Historically, yellow topaz was more commonly known, and the gem was often confused with other yellow stones. The modern association of topaz with blue is a relatively recent development, driven by technological advancements in gemstone treatment. It became an official December birthstone in 1952 when the Jewelry Industry Council of America updated the birthstone list.
Geological Formation and Sources
Topaz is a silicate mineral composed of aluminum and fluorine. It forms in igneous rocks, particularly in cavities within granites and rhyolites. Natural blue topaz is rare. Most of the blue topaz available today starts as colorless or pale topaz, which is then irradiated and heat-treated to produce the desired blue color. This process is stable and permanent. Major sources of topaz include Sri Lanka, Brazil, Mexico, Nigeria, and the United States. It is the official state gem of Texas.
Gemological Properties
Blue Topaz is known for its glass-like luster and deep cleavage, which can make it somewhat delicate despite its hardness. Its color range is extensive, with commercially available varieties including:
- Sky Blue Topaz: A light aqua color.
- Swiss Blue Topaz: A vibrant, medium-light blue.
- London Blue Topaz: A deep, inky blue color prized by collectors.
| Gemological Property | Blue Topaz |
|---|---|
| Chemical Formula | Al₂SiO₄(F,OH)₂ |
| Hardness (Mohs) | 8 |
| Crystal System | Orthorhombic |
| Refractive Index | 1.609 - 1.629 |
| Specific Gravity | 3.49 - 3.57 |
| Luster | Vitreous (glass-like) |
Symbolism and Metaphysical Beliefs
Blue Topaz is associated with wisdom, calmness, and clear communication. It is believed to soothe the mind, relieve stress, and promote truthful expression. The deep blue of London Blue Topaz is often linked to introspection and spiritual enlightenment.
Care and Cleaning
With a hardness of 8, Blue Topaz is very resistant to scratching and is the most durable of the four December stones. However, it has perfect cleavage in two directions, meaning it can be fractured by a sharp blow. It is also sensitive to heat and sudden temperature changes. Cleaning is straightforward with warm, soapy water and a soft brush. Ultrasonic cleaning is generally safe, but steam cleaning should be avoided.
Conclusion
The December birthstones offer a remarkable range of choices, from the ancient, earthy beauty of Turquoise to the fiery brilliance of Zircon, the rare violet-blue of Tanzanite, and the cool, durable elegance of Blue Topaz. Each gem carries its own story, geological journey, and set of properties, allowing those born in December to select a stone that truly resonates with their personal style and values. Whether one is drawn to the protective history of Turquoise, the rarity of Tanzanite, the brilliance of Zircon, or the modern appeal of Blue Topaz, these four gems ensure that December’s legacy in the world of birthstones is as vibrant and diverse as the winter sky.