December, the final month of the year, is associated with a rich and diverse selection of gemstones, all sharing a common theme: the color blue. The December birthstones—turquoise, tanzanite, blue zircon, and blue topaz—each offer unique characteristics, histories, and symbolism. This article delves into the gemological, historical, and cultural significance of these blue gems, providing a thorough understanding of their roles in both ancient traditions and contemporary jewelry.
Introduction
December's birthstones are celebrated for their vibrant blue hues and their long-standing association with protection, prosperity, and spiritual connection. While turquoise has held a prominent place in the list for millennia, the modern December birthstone collection has expanded to include tanzanite, blue zircon, and blue topaz. These gems not only reflect a spectrum of blue shades but also embody a range of meanings and uses across cultures and time periods. This article explores the properties, origins, symbolism, and care of these December birthstones, drawing from historical and gemological sources.
History and Lore
Ancient Associations
Turquoise has been revered for thousands of years. It was used by ancient Egyptians, who believed it had protective and healing powers. The pharaohs of Egypt adorned themselves with turquoise jewelry, which was often placed in tombs to ensure safe passage to the afterlife. Chinese artisans also used turquoise over 3,000 years ago, carving it into intricate designs and inlaying it into furniture and artifacts. In Mesoamerica, turquoise was considered a sacred stone, often worn by rulers and warriors as a symbol of power and divine favor.
Lapis lazuli, another blue gemstone, was historically considered a December birthstone before the 1950s. This gemstone, known for its deep blue color with flecks of gold, was prized by ancient civilizations such as the Egyptians and Mesopotamians for its beauty and spiritual significance. It was used in cosmetics, amulets, and even as a pigment in art.
Prior to 1912, ruby and bloodstone were also considered December birthstones. Ruby was believed to sharpen the mind and improve concentration, while bloodstone was thought to offer protection and vitality. These associations reflect the deep spiritual and practical roles that gemstones played in ancient societies.
The Modern Era
In the 20th century, the selection of December birthstones evolved. Tanzanite, discovered in 1967 in Tanzania, was officially recognized as a December birthstone in the United States in 2002. This gemstone, known for its striking blue to violet color, was marketed as a modern alternative to traditional blue gems. Its discovery was a significant event in gemology, as it was one of the few gemstones discovered in the 20th century.
Blue zircon, which replaced lapis lazuli as a December birthstone after 1952, is a versatile gemstone that can display a range of colors, including blue, green, and brown. It is often heat-treated to enhance its blue hue, making it a popular choice for jewelry. Zircon is believed to bring emotional balance and joy, and its quiet vibration is said to connect the wearer to spiritual sources.
Blue topaz was added to the December birthstone list more recently, with authorities deeming it worthy of the official collection. This gemstone, known for its gentle blue color, is associated with stimulating self-esteem and enhancing the ability to learn. Its popularity has grown, making it a modern and accessible option for December birthdays.
Geological Formation and Sources
Turquoise
Turquoise is formed in arid regions through the weathering of copper-bearing minerals. It typically forms in the oxidized zones of copper deposits and is found in a variety of geological settings, including limestone and sandstone. Major sources of turquoise include the United States (particularly Nevada and Arizona), Iran, China, and Egypt. The presence of matrix—remnants of the host rock—can affect the color and appearance of turquoise, with darker matrix lines often enhancing its visual appeal.
Tanzanite
Tanzanite is a type of zoisite that is found only in Tanzania, near the foot of Mount Kilimanjaro. Its unique blue to violet color is due to trace amounts of vanadium and the presence of trivalent iron. The gemstone's formation is linked to the specific geological conditions of the area, which include the collision of tectonic plates and the presence of hydrothermal fluids. Tanzanite's limited geographic origin makes it a rare and valuable gemstone.
Blue Zircon
Blue zircon is a variety of zircon that can be found in various parts of the world, including Australia, Cambodia, and Brazil. Zircon is a naturally occurring mineral that can form in a range of colors, including brown, yellow, red, and blue. The blue color is typically achieved through heat treatment, which removes the brown coloration and enhances the blue hue. Zircon is known for its high refractive index and dispersion, making it a brilliant and eye-catching gemstone.
Blue Topaz
Blue topaz is a form of topaz that can be found in several countries, including Brazil, Mexico, and the United States. The blue color is achieved through irradiation and heat treatment, which alters the crystal structure and enhances the color. Natural blue topaz is extremely rare, making treated blue topaz the most common form available in the market. Blue topaz is known for its clarity and brilliance, making it a popular choice for jewelry.
Gemological Properties
Turquoise
- Color: Blue to green, often with matrix patterns.
- Hardness: 5–6 on the Mohs scale.
- Refractive Index: 1.61–1.65.
- Luster: Waxy to sub-vitreous.
- Transparency: Opaque to semi-translucent.
- Chemical Composition: Hydrated phosphate of copper and aluminum (CuAl6(PO4)4(OH)8·4H2O).
Turquoise is a relatively soft gemstone that requires careful handling to avoid scratches and damage. Its porous nature means it can absorb oils and chemicals, so it should be cleaned with mild soap and water. The presence of matrix patterns can vary widely, with some stones having minimal matrix and others displaying intricate, web-like patterns.
Tanzanite
- Color: Blue to violet, with pleochroism.
- Hardness: 6–7 on the Mohs scale.
- Refractive Index: 1.694–1.701.
- Luster: Vitreous.
- Transparency: Transparent to translucent.
- Chemical Composition: Calcium aluminum silicate (CaAl2(SiO4)(OH)2).
Tanzanite exhibits pleochroism, meaning it displays different colors when viewed from different angles. This gemstone is relatively durable but can be sensitive to high heat and harsh chemicals. It should be cleaned with warm soapy water and a soft cloth.
Blue Zircon
- Color: Blue, green, brown, and other hues.
- Hardness: 6–7.5 on the Mohs scale.
- Refractive Index: 1.92–2.01.
- Luster: Vitreous.
- Transparency: Transparent.
- Chemical Composition: Zirconium silicate (ZrSiO4).
Blue zircon is known for its high refractive index and dispersion, which gives it a brilliant and sparkly appearance. It is relatively durable but can be sensitive to high heat and harsh chemicals. Blue zircon should be cleaned with warm soapy water and a soft cloth.
Blue Topaz
- Color: Blue, ranging from light to deep hues.
- Hardness: 8 on the Mohs scale.
- Refractive Index: 1.61–1.63.
- Luster: Vitreous.
- Transparency: Transparent.
- Chemical Composition: Aluminum silicate (Al2SiO6).
Blue topaz is one of the hardest December birthstones, making it suitable for everyday wear. It is relatively durable and can be cleaned with warm soapy water and a soft cloth. Natural blue topaz is rare, and most blue topaz in the market is treated to enhance its color.
Symbolism and Metaphysical Beliefs
Turquoise
Turquoise has long been associated with protection, prosperity, and good fortune. In ancient times, it was believed to protect the wearer from harm, particularly from falling. Hindu mystics believed that seeing turquoise after the new moon would bring wealth. Turquoise is also associated with communication and emotional balance, making it a popular choice for those seeking to enhance their ability to express themselves.
Tanzanite
Tanzanite is considered a protective and soothing stone that helps the wearer share spiritual information from their heart in a calm manner. It is believed to promote emotional balance and inner peace, making it a valuable tool for meditation and spiritual growth. Tanzanite is also associated with love and compassion, helping to foster deeper connections with others.
Blue Zircon
Blue zircon is believed to bring joy and emotional balance to the wearer. It is often used in meditation to connect with spiritual sources and to enhance one's ability to navigate complex ideas. Blue zircon is also associated with calming the mind and bringing a sense of peace and stability.
Blue Topaz
Blue topaz is associated with stimulating self-esteem and enhancing the ability to learn. It is believed to align the body's meridians and calm the emotions, making it an excellent stone for meditation and spiritual practices. Blue topaz is also associated with protection and good fortune, making it a popular choice for those seeking to attract positive energy.
Care and Cleaning
Turquoise
Turquoise is a relatively soft and porous gemstone, so it requires careful handling to avoid damage. It should be kept away from harsh chemicals, oils, and excessive heat. To clean turquoise, use mild soap and warm water. Gently scrub with a soft cloth or brush and pat dry with a clean towel. Avoid using ultrasonic or steam cleaners, as they can damage the stone.
Tanzanite
Tanzanite can be sensitive to high heat and harsh chemicals, so it should be cleaned carefully. Use warm soapy water and a soft cloth to clean tanzanite. Avoid using ultrasonic or steam cleaners, as they can cause the stone to become brittle or lose its color.
Blue Zircon
Blue zircon is relatively durable but can be sensitive to high heat and harsh chemicals. It should be cleaned with warm soapy water and a soft cloth. Avoid using ultrasonic or steam cleaners, as they can cause the stone to become brittle or lose its color.
Blue Topaz
Blue topaz is one of the hardest December birthstones and is relatively durable. It can be cleaned with warm soapy water and a soft cloth. It is also safe to use ultrasonic and steam cleaners for blue topaz, as it is resistant to heat and chemicals.
Conclusion
December's birthstones offer a rich tapestry of blue hues, each with its own unique properties, history, and symbolism. From the ancient allure of turquoise to the modern discovery of tanzanite, these gems have captivated people for centuries. Whether chosen for their beauty, their historical significance, or their metaphysical properties, December birthstones continue to be cherished by those born in this month. Understanding their gemological properties and proper care ensures that these gems can be enjoyed for generations to come.