December is a month rich in symbolism, celebration, and, in the world of gemology, a unique array of precious stones. Known for its winter charm and festive cheer, December is also distinguished by its collection of birthstones—four distinct blue gemstones that have captivated gemstone lovers for generations. These stones—Tanzanite, Turquoise, Zircon, and Blue Topaz—each bring their own unique characteristics, histories, and cultural significance to the table. This article provides an in-depth exploration of these December birthstones, covering their geological properties, historical and cultural significance, and practical care tips.
Historical and Cultural Significance
The tradition of associating gemstones with birth months has its roots in ancient times. Early references date back to biblical times, where the High Priest Aaron’s breastplate was adorned with 12 gemstones, each representing a tribe of Israel. While the exact stones and their assignments are debated, this early concept of connecting gems with specific months and people laid the foundation for the modern birthstone tradition.
By medieval times, the practice had evolved, and various cultures began to associate gemstones with specific months and their symbolic meanings. In the early 20th century, the American National Retail Jewelers Association (now the Jewelers of America) formalized the list of birthstones, establishing a standardized system that is still followed today. December, in this formalization, was initially assigned two gemstones: Turquoise and Zircon. However, in 1961, the list was updated to include Tanzanite, a relatively new discovery, and in more recent times, Blue Topaz has also been recognized as a December birthstone.
The choice of blue as a dominant color for December birthstones is not arbitrary. Blue has long been associated with calmness, wisdom, and protection. In many cultures, blue gemstones were believed to offer protection and bring good fortune. This belief was especially prevalent in ancient Egypt and the Middle East, where Turquoise was highly prized for its protective and healing properties.
Geological Formation and Sources
Tanzanite
Tanzanite is a relatively modern discovery in the gemstone world. It was first found in 1967 in the Merelani Hills of Tanzania, near Mount Kilimanjaro. This gemstone is a variety of the mineral zoisite and is known for its vibrant blue to violet color. What makes Tanzanite particularly fascinating is its pleochroism, meaning it displays different colors when viewed from different angles. Tanzanite typically appears blue when viewed from one angle and violet from another.
Tanzanite is a metamorphic gemstone, formed through the transformation of existing rock under intense heat and pressure. The unique conditions required for Tanzanite to form are rare, which is why it is only found in the Merelani Hills. This exclusivity adds to its allure and value.
Turquoise
Turquoise is one of the oldest known gemstones and has been used for thousands of years in jewelry, carvings, and decorative objects. It is a hydrated phosphate of aluminum and copper, typically found in arid regions. The blue-green color of turquoise is due to the presence of copper, while the greenish hues result from iron.
The most historically significant sources of turquoise are the mines in ancient Egypt, particularly the Sinai Peninsula. However, the most important sources today are in the United States, especially in New Mexico, Arizona, and Nevada. Turquoise is also mined in China, Iran, and Mexico, each producing distinct varieties of the gemstone.
Turquoise is a relatively soft gemstone, with a hardness of 5–6 on the Mohs scale. This means it is prone to scratching and requires careful handling and appropriate settings in jewelry.
Zircon
Zircon is a mineral that has been known for centuries and has been used in various cultures for its aesthetic and metaphysical properties. It is a zirconium silicate and is found in a wide range of colors, including blue, green, yellow, red, and brown. The blue variety of zircon is particularly popular as a December birthstone.
Zircon forms in igneous rocks and is often found in metamorphic and sedimentary environments as well. The blue color of zircon is achieved through a heat treatment process that changes the color of the gemstone. This treatment is stable and does not fade over time.
Zircon is found in many parts of the world, including Australia, Cambodia, India, and the United States. The most significant sources for high-quality blue zircon are in Cambodia and India.
Blue Topaz
Blue Topaz is a variety of the mineral topaz, which is a silicate of aluminum and fluorine. The blue color of this gemstone is due to trace amounts of iron and irradiation during its formation. Blue Topaz is known for its clarity, brilliance, and affordability, making it a popular choice for jewelry.
Topaz is one of the hardest gemstones, with a hardness of 8 on the Mohs scale, making it durable and suitable for everyday wear. Blue Topaz is primarily mined in Brazil, though it is also found in other countries such as Nigeria and the United States.
Gemological Properties
Tanzanite
- Chemical Composition: Calcium aluminum silicate (CaAl₂(SiO₄)(OH)₂)
- Color: Blue to violet (pleochroic)
- Hardness: 6–7 on the Mohs scale
- Refractive Index: 1.694–1.706
- Luster: Vitreous
- Transparency: Transparent to translucent
- Origin: Tanzania
- Special Properties: Pleochroism (displays different colors when viewed from different angles)
Turquoise
- Chemical Composition: Hydrated phosphate of aluminum and copper (Al₂(OH)PO₄)
- Color: Blue to greenish-blue
- Hardness: 5–6 on the Mohs scale
- Refractive Index: 1.61–1.65
- Luster: Waxy to greasy
- Transparency: Translucent to opaque
- Origin: United States, Iran, China, Mexico
- Special Properties: Chatoyancy (fibrous structure may display a cat's eye effect)
Zircon
- Chemical Composition: Zirconium silicate (ZrSiO₄)
- Color: Blue (treated), green, yellow, brown, red
- Hardness: 6–7.5 on the Mohs scale
- Refractive Index: 1.92–2.01
- Luster: Vitreous
- Transparency: Transparent
- Origin: Australia, Cambodia, India, United States
- Special Properties: Dispersion (fire), double refraction
Blue Topaz
- Chemical Composition: Aluminum silicate fluoride (Al₂SiO₄(F,OH)₂)
- Color: Blue (due to trace elements and irradiation)
- Hardness: 8 on the Mohs scale
- Refractive Index: 1.62–1.64
- Luster: Vitreous
- Transparency: Transparent
- Origin: Brazil, Nigeria, United States
- Special Properties: High clarity, brilliance
| Gemstone | Color | Hardness (Mohs) | Chemical Composition | Origin |
|---|---|---|---|---|
| Tanzanite | Blue to violet | 6–7 | Calcium aluminum silicate | Tanzania |
| Turquoise | Blue to greenish-blue | 5–6 | Hydrated phosphate of aluminum and copper | United States, Iran, China, Mexico |
| Zircon | Blue (treated) | 6–7.5 | Zirconium silicate | Australia, Cambodia, India, United States |
| Blue Topaz | Blue | 8 | Aluminum silicate fluoride | Brazil, Nigeria, United States |
Symbolism and Metaphysical Beliefs
Each of the December birthstones carries its own set of symbolic meanings and metaphysical properties, which have been attributed to them by various cultures throughout history.
Tanzanite
Tanzanite is often associated with transformation, intuition, and emotional healing. It is believed to enhance spiritual growth and encourage self-discovery. In metaphysical practices, Tanzanite is used to open the heart and throat chakras, promoting communication and emotional balance.
Turquoise
Turquoise has long been revered for its protective and calming properties. In ancient Egypt, it was used to ward off evil spirits and was often placed in tombs to protect the deceased. In Native American cultures, Turquoise is considered a sacred stone, representing wisdom, health, and prosperity. It is also believed to enhance communication and attract positive energy.
Zircon
Zircon is associated with mental clarity, confidence, and protection. In the Middle Ages, it was believed that Zircon could lull one into a deep sleep and protect against evil spirits. Modern metaphysical beliefs suggest that Zircon enhances memory and promotes a sense of calm and balance.
Blue Topaz
Blue Topaz is linked to inner strength, creativity, and wisdom. It is believed to increase mental clarity and enhance one's ability to think clearly and make sound decisions. Blue Topaz is also associated with love, beauty, and emotional healing.
Choosing the Right December Birthstone
With four beautiful blue gemstones to choose from, selecting the right December birthstone can be a personal decision based on individual preferences and needs. Here are some considerations to help make the choice:
- Personal Connection: Choose a gemstone that resonates with you on a personal level. If you feel drawn to the vibrant colors of Tanzanite or the calming hues of Turquoise, that may be the right choice for you.
- Practicality: Consider the durability of the gemstone. Blue Topaz and Zircon are harder and more suitable for everyday wear, while Turquoise and Tanzanite require more careful handling.
- Symbolism: Reflect on the symbolic meanings of each gemstone. If you are seeking emotional healing, Tanzanite or Turquoise may be the best choice. If you are looking for mental clarity and confidence, Zircon or Blue Topaz may be more suitable.
Care and Cleaning
Proper care is essential to maintaining the beauty and longevity of December birthstones. Here are some care and cleaning tips for each gemstone:
Tanzanite
- Cleaning: Clean Tanzanite with warm, soapy water and a soft cloth. Avoid using ultrasonic cleaners, as they can damage the gemstone.
- Storage: Store Tanzanite separately from harder gemstones to prevent scratches. Keep it in a soft pouch or a lined jewelry box.
Turquoise
- Cleaning: Clean Turquoise with a soft cloth and mild soap. Avoid using harsh chemicals or ultrasonic cleaners, as they can damage the gemstone.
- Storage: Store Turquoise in a cool, dry place away from direct sunlight and other gemstones to prevent scratches and discoloration.
Zircon
- Cleaning: Clean Zircon with warm, soapy water and a soft cloth. Avoid using ultrasonic cleaners, as they can cause the gemstone to become cloudy.
- Storage: Store Zircon separately from harder gemstones to prevent scratches. Keep it in a soft pouch or a lined jewelry box.
Blue Topaz
- Cleaning: Clean Blue Topaz with warm, soapy water and a soft cloth. It can also be cleaned with an ultrasonic cleaner.
- Storage: Store Blue Topaz separately from harder gemstones to prevent scratches. Keep it in a soft pouch or a lined jewelry box.
Conclusion
December is a month of celebration, and its birthstones—Tanzanite, Turquoise, Zircon, and Blue Topaz—add to the charm with their rich history, symbolic meanings, and stunning beauty. Each of these gemstones offers a unique combination of color, durability, and cultural significance, making them a wonderful choice for jewelry and personal adornment. Whether you are drawn to the vibrant blue of Tanzanite, the calming hues of Turquoise, the brilliance of Zircon, or the clarity of Blue Topaz, there is a December birthstone to suit every taste and occasion.
Understanding the geological properties, historical significance, and care requirements of these gemstones allows for a deeper appreciation of their beauty and value. Whether worn for personal enjoyment, as a meaningful gift, or as a symbol of December birthdays, these blue treasures continue to captivate and inspire.