December, the final month of the calendar year, is marked by a rich tapestry of birthstones that reflect the diversity of its cultural, historical, and geological significance. Unlike months with a single designated birthstone, December is associated with four distinct gemstones: Turquoise, Tanzanite, Zircon, and Blue Topaz. These stones vary in color, hardness, and symbolism, offering a wide range of options for jewelry and personal adornment. This article explores the gemological properties, historical and cultural lore, and practical considerations for each of these December birthstones, drawing from authoritative and historical sources.
Historical and Cultural Significance
The concept of birthstones has ancient roots, often tied to religious and spiritual beliefs. For December, the list of birthstones includes both traditional and modern additions. The Turquoise has long been a favored gem in ancient civilizations, while the Tanzanite, discovered in the 20th century, brings a modern flair to the December lineup. Zircon and Blue Topaz offer additional options in terms of color and durability.
Turquoise: The Ancient Stone of Protection and Fortune
Turquoise is the most historically significant of December’s birthstones. Known for its striking blue-green hues, it has been treasured for millennia. The name "turquoise" derives from the French pierre turquoise, meaning "Turkish stone," referring to the trade routes through which it entered Europe from the East.
Historically, turquoise was believed to offer protective qualities. In Ancient Egypt, it was found in the tombs of pharaohs and was associated with the goddess Hathor, who symbolized love, beauty, and motherhood. It was also used in Persia and the Near East, where it was carved into amulets and seals, especially during the reigns of Kings Darius and Artaxerxes.
In Tibet, turquoise was not only a gemstone but also a currency. It was believed to bring fortune, health, and success. In the New World, Native American tribes, including the Pueblo and Navajo, used turquoise in jewelry and ceremonial objects. They believed it symbolized youth, strength, and vitality, and it was also considered a love stone, helping to preserve relationships.
Tanzanite: A Modern Discovery with Ancient Appeal
Tanzanite is a relatively new gemstone on the birthstone scene. Discovered in Tanzania in 1967, it was initially mistaken for columbite, a black mineral. The transformation of tanzanite into its beautiful violet-blue color occurs only through heat treatment, which was a crucial step in making the gem commercially viable.
The gem was named after Tanzania, the country of its origin, and it has since gained popularity for its vibrant color and trichroic nature—it displays three different colors depending on the viewing angle. It is also believed to carry spiritual and emotional healing properties, and it is said to promote inner peace and balance.
Zircon: The Timeless Sparkler
Zircon is one of the oldest minerals on Earth, with some zircon crystals found in Australia dating back over 4 billion years. It is a versatile gemstone that occurs in a variety of colors, including blue, green, red, and brown. The blue variety, which is often treated to enhance its color, is the one most commonly associated with December.
Zircon has a long history of use in jewelry and amulets, and it was once known as the "gemstone of the future" due to its brilliance and fire. It was especially popular in Victorian and Art Deco jewelry. Zircon is also believed to have protective qualities, and it was used in ancient times to ward off negativity and danger.
Blue Topaz: A Durable and Radiant Choice
Blue topaz is another relatively modern addition to the December birthstone list. Naturally occurring blue topaz is rare, and most of the blue topaz available today is treated with irradiation or heat to enhance its color. The result is a gemstone with a brilliant blue hue, often described as "sky blue" or "London blue."
Topaz, in general, has been valued for its durability and brilliance. In Ancient Egypt, it was believed to be a gift from the sun god Ra, and it was used in protective amulets. The Mohs hardness of 8 makes blue topaz suitable for daily wear, and it is often used in rings, pendants, and earrings.
Geological Formation and Sources
Each of December's birthstones has a unique geological origin and is found in specific locations around the world.
Turquoise: A Product of Hydrothermal and Weathering Processes
Turquoise is a phosphate mineral composed of copper and aluminum. It forms in hydrothermal veins and weathered igneous rocks, often in arid climates where water can carry minerals to the surface. The presence of iron and other elements gives turquoise its characteristic blue-green color. The veins and spiderweb patterns seen in turquoise are caused by matrix inclusions from the surrounding rock.
Major sources of turquoise include:
- Iran (Persia) – historically the primary source
- Egypt – known for its ancient turquoise deposits
- Tibet and China
- The Americas – especially in Arizona, New Mexico, and Nevada in the United States
Tanzanite: A Unique and Rare Mineral
Tanzanite is a trigonal mineral composed of calcium aluminum silicate. It is found only in Tanzania, specifically in the Merelani Hills near Arusha. The gem's violet-blue color is due to the presence of vanesite, a trace element that is activated through heat treatment. Without this treatment, tanzanite appears black or brown.
Tanzanite is relatively soft, with a Mohs hardness of 6 to 7, which means it requires careful handling. It is also anisotropic, meaning it can show different colors from different angles.
Zircon: From Ancient Crystals to Modern Jewelry
Zircon is a zirconium silicate that forms in igneous and metamorphic rocks. It is known for its high refractive index, which gives it a sparkling appearance. Zircon can be found in a wide range of colors, including blue, green, yellow, brown, and colorless. The blue variety is the most popular in jewelry, and it is created through heat treatment.
Zircon is found in many parts of the world, including:
- Australia – home to some of the oldest zircon crystals
- Brazil
- Madagascar
- India
- Zimbabwe
- Thailand
Blue Topaz: A Radiant and Durable Gem
Blue topaz is a silicate mineral composed of aluminum and fluorine. It is found in granite pegmatites and metamorphic rocks. Naturally occurring blue topaz is rare, so most of the blue topaz on the market is treated to enhance its color.
Blue topaz is found in:
- Brazil – the primary source
- Nigeria
- Australia
- United States
Gemological Properties and Care
Understanding the physical and chemical properties of December's birthstones is essential for both collectors and jewelers. These properties determine the gem's suitability for jewelry, durability, and care requirements.
| Gemstone | Color | Hardness (Mohs) | Chemical Formula | Transparency | Luster | Cleavage | Special Properties |
|---|---|---|---|---|---|---|---|
| Turquoise | Blue-Green | 5-6 | CuAl₆(PO₄)₄(OH)₈·4H₂O | Opaque to Translucent | Waxy, Dull | None | Matrix patterns, porosity |
| Tanzanite | Violet-Blue | 6-7 | Ca₂Al₃(SiO₄)₃(OH) | Transparent | Vitreous | Perfect | Trichroism, heat-sensitive |
| Zircon | Blue, Green, Yellow | 6.5-7.5 | ZrSiO₄ | Transparent to Translucent | Vitreous | Good | High refractive index, double refraction |
| Blue Topaz | Blue | 8 | Al₂SiO₄(F,OH)₂ | Transparent | Vitreous | Perfect | Radiation-induced color, high brilliance |
Care and Maintenance
Each of these gemstones requires specific care to maintain its beauty and integrity.
Turquoise is porous and sensitive to chemicals and heat. It should be stored in a cool, dry place and cleaned with a soft cloth and mild soap. Avoid exposure to sunlight or strong solvents.
Tanzanite is heat-sensitive, so it should not be exposed to high temperatures or direct sunlight for extended periods. It should be avoided from harsh chemicals and stored separately from harder gemstones to prevent scratches.
Zircon has good durability but can be chipped if struck hard. It should be cleaned gently with warm water and a soft brush. Avoid high heat and harsh chemicals, as they can damage the gem's color.
Blue Topaz is very durable and can be cleaned with standard jewelry cleaning methods, including ultrasonic cleaners and steam cleaners. It is resistant to scratches and abrasion, making it an excellent choice for daily wear.
Symbolism and Metaphysical Beliefs
December’s birthstones are not only valued for their beauty and durability but also for their symbolic and spiritual significance. These beliefs have been passed down through generations and continue to influence modern perceptions of these gemstones.
Turquoise: A Symbol of Protection and Harmony
Turquoise has long been associated with protection, health, and good fortune. In Ancient Egypt, it was believed to be a divine stone, linked to Hathor, the goddess of love and motherhood. In Persia, it was used as a seal stone by kings and nobles, symbolizing authority and power.
In Native American culture, turquoise is considered a healing stone that brings positive energy and balance. It is often used in ceremonies and rituals to promote spiritual growth and emotional stability.
Tanzanite: A Stone of Emotional Healing
Tanzanite is believed to have strong emotional and spiritual properties. It is associated with inner peace, emotional balance, and spiritual awakening. It is often used in healing practices to soothe anxiety and promote compassion.
In modern crystal therapy, tanzanite is said to open the heart and throat chakras, encouraging honest communication and emotional healing.
Zircon: A Stone of Clarity and Protection
Zircon is often referred to as the "stone of the future" due to its brilliant and fiery appearance. It is believed to enhance clarity of thought, promote wisdom, and provide protection against negative energy.
In Victorian times, zircon was used as a protective amulet, especially for travellers and those in perilous situations. It was also thought to ward off nightmares and bring good dreams.
Blue Topaz: A Stone of Strength and Positivity
Blue topaz is associated with strength, positivity, and emotional balance. It is believed to enhance one's ability to cope with stress and anxiety, making it a popular choice for those seeking emotional stability.
In Ancient Egypt, blue topaz was used in protective amulets to ward off evil spirits and negative influences. It was also thought to bring good luck and prosperity to its wearer.
Conclusion
December's birthstones—Turquoise, Tanzanite, Zircon, and Blue Topaz—offer a fascinating blend of historical significance, geological diversity, and spiritual symbolism. Each gemstone has its own unique properties, origins, and uses, making them valuable not only as jewelry but also as symbols of personal and cultural identity.
Whether you choose a turquoise ring to honor ancient traditions, a tanzanite pendant for emotional healing, a zircon necklace for clarity and protection, or a blue topaz bracelet for strength and positivity, these gemstones continue to inspire and captivate. Understanding their scientific properties, historical roles, and cultural meanings can deepen your appreciation for these timeless treasures.