December, the final month of the year, is uniquely distinguished by its association with four official birthstones: Turquoise, Tanzanite, Blue Zircon, and Blue Topaz. This multiplicity is not only a testament to the month’s rich gemological diversity but also reflects evolving traditions in the jewelry industry and the cultural significance of these blue-hued stones. Each of these December birthstones carries its own unique history, symbolism, and physical properties, making them compelling choices for those born in this month or seeking meaningful gemstone jewelry.
This article explores the origins, characteristics, and cultural meanings of each of these December birthstones. From the ancient allure of Turquoise to the modern discovery of Tanzanite, we delve into the science, history, and symbolism behind these gems, supported by expert sources and historical context.
History and Lore
The tradition of assigning specific gemstones to months of the year dates back to ancient times. The earliest known references to birthstones are found in the Breastplate of Aaron, a sacred Jewish artifact mentioned in the Old Testament. However, the modern system of birthstones as it is known today was largely formalized in the 20th century by the jewelry trade.
December, in particular, has an intriguing place in the birthstone tradition. Unlike most months, which are associated with a single gemstone, December is unique in that it has four recognized birthstones. This multiplicity was introduced in part to accommodate the variety of blue gemstones and to offer consumers a broader range of aesthetic and affordability options.
The earliest December birthstone was Turquoise, a gemstone with a long and storied history that predates modern civilization. Turquoise has been used for thousands of years in jewelry and ornamentation across various cultures, including the ancient Egyptians, Persians, and Native Americans. Its name derives from the French pierre turquoise, meaning “Turkish stone,” a reference to the trade routes through which the stone entered Europe.
Blue Zircon, a relatively newer addition to the December birthstone list, was officially recognized in 1952. It is a naturally occurring gemstone that can be found in a range of blue shades, from light to deep blue, and is prized for its brilliance and affordability.
Tanzanite, the most recent addition, was added to the list in 2002. It is a rare gemstone found only in a specific region of Tanzania. Discovered in the 1960s, it quickly gained popularity due to its striking violet-blue color and its association with transformation and healing.
Blue Topaz, though not officially added until the 20th century, has long been appreciated for its clarity and brilliance. It was designated as a December birthstone in 1912 and is the hardest of the four, with a Mohs hardness of 8.
Geological Formation and Sources
Understanding the formation and sources of a gemstone is essential for appreciating its rarity and value. Each of the December birthstones has distinct geological origins and mining locations.
Turquoise
Turquoise is a phosphate mineral formed through a process involving copper-rich groundwater that seeps into phosphate-bearing rock. Over time, chemical reactions between the copper and other minerals create the characteristic blue and green hues. The presence of matrix—the surrounding rock material—gives turquoise its distinctive patterns of dark lines and shapes.
Historically, the most famous turquoise deposits were in Persia (modern-day Iran), but today, the primary sources include Nevada and Arizona in the United States, China, and Mexico. The U.S. state of Texas has even designated turquoise as its official state gem.
Tanzanite
Tanzanite is a variety of the mineral zoisite and is found only in a narrow corridor of northern Tanzania, near the Mount Kilimanjaro range. It was discovered in the 1960s by a Masai herdsman and was later marketed as a unique gemstone. Its formation involves the transformation of zoisite under intense heat and pressure, resulting in the characteristic violet-blue color that deepens in intensity when heated.
Due to its exclusive geographic origin, tanzanite is considered one of the rarest of the December birthstones. Its limited availability makes it highly valuable, especially in larger, well-colored stones.
Blue Zircon
Zircon is a zirconium silicate mineral that occurs in a variety of colors, including colorless, yellow, and blue. The blue color in zircon is achieved through heat treatment, which enhances its natural properties and gives it a brilliant, fire-like dispersion.
Natural blue zircon is found in locations such as India, Brazil, and Cambodia, and it is known for its high refractive index, which gives it a sparkling appearance. It was officially added to the December birthstone list in 1952 by the Jewelry Industry Council of America, due to its affordability and aesthetic appeal.
Blue Topaz
Topaz is a silicate mineral with a hexagonal crystal structure and is one of the hardest December birthstones, with a Mohs hardness of 8. Blue topaz is not naturally blue; it is typically colorless or pale yellow, and the blue color is achieved through irradiation and heat treatment.
Natural blue topaz deposits are found in Sri Lanka, Brazil, Mexico, Nigeria, and the United States. The U.S. state of Texas also recognizes blue topaz as its official state gem. Its hardness and durability make it a popular choice for everyday wear, and its affordability has contributed to its widespread use in jewelry.
Gemological Properties
Each of the December birthstones has unique gemological properties that distinguish it from the others. These properties include hardness, refractive index, color, and clarity, all of which impact the stone’s durability, appearance, and value.
Turquoise
- Hardness: 5–6 on the Mohs scale, making it relatively soft and prone to scratches and damage.
- Refractive Index: 1.61–1.65
- Color: Ranges from sky blue to greenish-blue, often with matrix patterns.
- Clarity: Naturally opaque, with inclusions considered part of its charm.
Tanzanite
- Hardness: 6–7 on the Mohs scale.
- Refractive Index: 1.694–1.701
- Color: Deep violet-blue, often with a trichroic effect, meaning it shows three different colors when viewed from different angles.
- Clarity: Typically clear to slightly included, with eye-clean stones being highly desirable.
Blue Zircon
- Hardness: 7.5 on the Mohs scale.
- Refractive Index: 1.92–2.01
- Color: Varies from deep blue to bright blue, with high dispersion.
- Clarity: Often clear, though inclusions may be present.
Blue Topaz
- Hardness: 8 on the Mohs scale, the hardest of the December birthstones.
- Refractive Index: 1.619–1.627
- Color: Ranges from pale blue to deep blue, with the most valuable stones exhibiting a rich, even color.
- Clarity: Typically clear and eye-clean, making it ideal for everyday wear.
| Gemstone | Hardness (Mohs) | Refractive Index | Color Range | Clarity |
|---|---|---|---|---|
| Turquoise | 5–6 | 1.61–1.65 | Blue, greenish-blue | Opaque, with matrix |
| Tanzanite | 6–7 | 1.694–1.701 | Violet-blue | Clear to slightly included |
| Blue Zircon | 7.5 | 1.92–2.01 | Blue, bright blue | Clear to included |
| Blue Topaz | 8 | 1.619–1.627 | Pale blue to deep blue | Clear, eye-clean |
Symbolism and Metaphysical Beliefs
Each of the December birthstones has been attributed with symbolic meanings and metaphysical properties, often rooted in historical traditions and cultural beliefs.
Turquoise
Turquoise has long been associated with protection, good fortune, and wisdom. In ancient Egypt, it was used in amulets to ward off evil and was believed to bring prosperity. Native American tribes used turquoise in rituals and jewelry, associating it with healing and spiritual power.
In modern times, turquoise is believed to enhance communication, boost confidence, and promote emotional healing. Some sources also claim it supports the immune system and detoxification, making it a popular choice for holistic wellness practices.
Tanzanite
Tanzanite is associated with transformation, intuition, and emotional healing. Its rare and fleeting nature makes it a symbol of new beginnings and inner change. It is often recommended for those undergoing personal or spiritual growth, as it is believed to open the heart and mind to new possibilities.
Tanzanite is also linked to compassion and calmness, making it a beneficial stone for those seeking emotional balance and mental clarity.
Blue Zircon
Blue zircon is believed to promote restful sleep, attract wealth, and enhance wisdom. In ancient times, zircon was thought to bring protection and good luck to travelers. In modern metaphysical practices, blue zircon is associated with mental clarity and spiritual insight.
It is also believed to enhance memory and focus, making it a popular choice for students and professionals seeking mental sharpness.
Blue Topaz
Blue topaz is associated with calmness, clarity, and emotional stability. It is believed to help reduce anxiety and stress, promoting a peaceful and positive mindset. Some sources claim it enhances love and affection, making it a popular gemstone for romantic jewelry.
It is also linked to good fortune and success, and is often used in jewelry to attract prosperity and confidence.
Care and Cleaning
Proper care is essential for preserving the beauty and longevity of December birthstone jewelry. Each gemstone has different hardness, sensitivity to heat, and susceptibility to damage, so understanding how to care for each is crucial.
Turquoise
Due to its low hardness and porous structure, turquoise requires gentle handling. Avoid exposure to water, chemicals, and extreme temperatures, as these can cause cracking, discoloration, or matrix fading. Cleaning should be done with a soft cloth and mild soap, and it should be stored separately from harder gemstones to prevent scratches.
Tanzanite
Tanzanite is relatively soft and sensitive to heat and light. It should be stored in a dark place to prevent color fading and should be avoided when exposed to direct sunlight for extended periods. Cleaning can be done with a soft brush and mild soap, but ultrasonic cleaners should be avoided, as they may cause microfractures in the stone.
Blue Zircon
Blue zircon is moderately durable, but it should be handled carefully to avoid chips or scratches. It is safe to clean with warm water and a soft brush, and ultrasonic cleaners are generally acceptable, though steam cleaning should be avoided.
Blue Topaz
Blue topaz is the most durable of the December birthstones, with a hardness of 8 on the Mohs scale. It can be cleaned with warm water and a soft brush, and ultrasonic and steam cleaners are safe to use. It is also resistant to heat and chemicals, making it ideal for daily wear and long-term use.
Conclusion
December is a month rich in gemological diversity, symbolized by the four official birthstones: Turquoise, Tanzanite, Blue Zircon, and Blue Topaz. Each of these gemstones brings its own unique beauty, history, and meaning, making them compelling choices for those born in December or for anyone seeking meaningful jewelry.
From the ancient significance of Turquoise to the modern discovery of Tanzanite, these gemstones reflect both historical traditions and contemporary appreciation. Understanding their physical properties, symbolism, and care requirements allows for a deeper appreciation of their value and beauty.
Whether you are drawn to the healing properties of turquoise, the rare elegance of tanzanite, the sparkling brilliance of blue zircon, or the durable charm of blue topaz, each of these gemstones offers a distinct connection to the month of December and the qualities it represents.