December is a month of winter wonder, holiday cheer, and an intriguing distinction in the world of gemstones: it is the only month with four officially recognized birthstones. These include tanzanite, turquoise, blue zircon, and blue topaz. Each of these gemstones carries its own unique history, distinct gemological properties, and symbolic meaning, making them ideal choices for jewelry and personal adornment. This article explores the origins, characteristics, cultural significance, and care requirements of each of these December birthstones, drawing from historical, geological, and cultural sources to present a comprehensive overview.
The tradition of associating gemstones with specific months is an ancient practice, believed to have originated in Mesopotamia and later adopted by the ancient Greeks and Romans. Over time, the December birthstone list has evolved. Originally, only turquoise and zircon were considered December's gemstones. However, in the 20th century, the list expanded to include blue topaz and tanzanite, with the latter being the most recent addition in 2002, as recognized by the American Gem Trade Association (AGTA). This expansion reflects not only the evolving nature of the birthstone tradition but also the growing appreciation for new gemstone discoveries and their commercial appeal.
December's birthstones are all characterized by their blue hues, a nod to the cool tones of winter and the calmness associated with the season. While all four stones are blue, they differ in color depth, composition, and historical significance. This article will explore each of these gemstones in detail, covering their geological formation, cultural symbolism, and care requirements, based on the information provided in the sources.
History and Lore of December Birthstones
The history of December birthstones is as rich and varied as the gemstones themselves. Turquoise, for instance, has a long and storied past. It is one of the oldest known gemstones, with a history that dates back to ancient Egypt, where it was revered for its protective qualities and believed to bring good fortune. Ancient Egyptians used turquoise in jewelry and amulets, often inlaying it into gold and ivory.
In ancient Persia, turquoise was considered a sacred stone and was used to create elaborate jewelry and decorative objects. The Aztecs and Native American tribes also held turquoise in high regard, using it in ceremonial regalia and as a symbol of protection and spiritual connection.
Zircon, another of the traditional December birthstones, has an equally rich history. It has been known and used since ancient times, with evidence of its use in Mesopotamian and Egyptian jewelry. Zircon is found in a wide range of colors, from colorless to yellow, red, and blue. In the 1960s, zircon was heated to transform it into the brilliant blue gem we now associate with December. This process, known as heat treatment, was a significant advancement in gemology.
Blue topaz became a more modern addition to the December birthstone list. It is a relatively recent discovery, with large deposits found in the 1960s and 1970s. Blue topaz is typically colorless in its natural state but can be irradiated and heat-treated to produce a beautiful blue color. It quickly gained popularity for its affordability and durability.
The most recent addition to the December birthstone list is tanzanite. Discovered in Northern Tanzania in 1967, it was named after its country of origin. Tanzanite is a rare gemstone, found only in the Merelani Hills of Tanzania. It is known for its deep blue-violet color and was officially recognized as a December birthstone in 2002 by the AGTA. Its discovery and subsequent rise in popularity mark a significant development in the world of gemstones.
Geological Formation and Sources
Understanding the geological formation and sources of December birthstones provides insight into their rarity, beauty, and value. Each of these gemstones has unique geological properties that contribute to their distinct characteristics.
Turquoise
Turquoise is a phosphorus-rich hydrated aluminum mineral that forms in arid regions. It is typically found in low-temperature environments, such as cavities and fractures in volcanic rock, where water percolates through the rock and deposits minerals. The blue-green color of turquoise is due to the presence of copper, while the yellow or brown tones are caused by iron impurities.
Major sources of turquoise include the United States (especially Nevada and New Mexico), China, Egypt, and Iran. The quality and color of turquoise can vary depending on the location and the minerals present in the soil. High-quality turquoise with a rich, even blue color is considered the most valuable.
Tanzanite
Tanzanite is a trigonal mineral that forms in metamorphic rocks under high heat and pressure. It is a variety of the mineral columbite-tantalite, and its deep blue-violet color is due to the presence of vanadium. Tanzanite is only found in the Merelani Hills of Tanzania, making it one of the rarest gemstones in the world.
The Merelani Hills are part of a large pegmatite deposit, and tanzanite is formed when the rocks in this area undergo metamorphism. The gemstone is often found in crystalline form, and its color can vary from deep blue to violet, depending on the angle of light and the presence of impurities.
Blue Zircon
Zircon is a zirconium silicate mineral that forms in igneous rocks such as granite and basalt. It is known for its high refractive index and dispersion, giving it a brilliant, diamond-like sparkle. Natural zircon can be found in a wide range of colors, including colorless, yellow, red, and blue.
Blue zircon is created through a process called heat treatment, which transforms the natural color of zircon into a beautiful blue hue. This process involves heating the gemstone to high temperatures, which alters the crystal structure and enhances the blue color. Zircon is found in many parts of the world, including Australia, Brazil, and Sri Lanka.
Blue Topaz
Blue topaz is a silicate mineral that forms in hydrothermal veins and pegmatites. In its natural state, blue topaz is colorless, but it can be treated to produce a beautiful blue color. The process involves irradiation and heat treatment, which alters the crystal structure and enhances the blue color.
Blue topaz is found in several countries, including the United States (especially Colorado), Brazil, and Nigeria. It is known for its hardness (8 on the Mohs scale) and affordability, making it a popular choice for jewelry.
Gemological Properties
Each of the December birthstones has unique gemological properties that contribute to their beauty, durability, and value. Understanding these properties helps in selecting the right gemstone for jewelry and in caring for it properly.
Turquoise
- Chemical Formula: CuAl₆(PO₄)₄(OH)₈·4H₂O
- Color: Sky blue to greenish-blue
- Hardness (Mohs scale): 5–6
- Refractive Index: 1.61–1.65
- Luster: Waxy to greasy
- Transparency: Opaque
- Cleavage: None
- Fracture: Uneven
- Specific Gravity: 2.6–2.8
Turquoise is a relatively soft gemstone with a waxy luster. It is opaque and often contains inclusions or veins of other minerals. Due to its low hardness, it is more prone to scratches and damage, and it requires careful handling.
Tanzanite
- Chemical Formula: Ca₂Al₃(SiO₄)₃(OH)
- Color: Deep blue to violet
- Hardness (Mohs scale): 6–7
- Refractive Index: 1.694–1.700
- Luster: Vitreous
- Transparency: Translucent to transparent
- Cleavage: Perfect
- Fracture: Conchoidal
- Specific Gravity: 3.14–3.38
Tanzanite is a relatively soft gemstone with a perfect cleavage, making it susceptible to chipping or breaking if not handled carefully. It has a high refractive index and a beautiful vitreous luster. Its deep blue-violet color is enhanced through heat treatment.
Blue Zircon
- Chemical Formula: ZrSiO₄
- Color: Blue, colorless, yellow, red
- Hardness (Mohs scale): 6–7.5
- Refractive Index: 1.92–2.01
- Luster: Vitreous
- Transparency: Transparent to translucent
- Cleavage: None
- Fracture: Conchoidal
- Specific Gravity: 4.6–4.7
Blue zircon is a high refractive index gemstone with a brilliant, diamond-like sparkle. It is more durable than turquoise and tanzanite, making it a good choice for everyday jewelry. It is often heat-treated to enhance its blue color.
Blue Topaz
- Chemical Formula: Al₂SiO₄(F,OH)₂
- Color: Colorless to blue
- Hardness (Mohs scale): 8
- Refractive Index: 1.61–1.63
- Luster: Vitreous
- Transparency: Transparent
- Cleavage: None
- Fracture: Uneven
- Specific Gravity: 3.5–3.6
Blue topaz is one of the hardest December birthstones, making it a durable and long-lasting gemstone. It is often treated with irradiation and heat to produce its beautiful blue color. Its high hardness and low maintenance make it an excellent choice for jewelry.
Symbolism and Metaphysical Beliefs
The December birthstones are not only valued for their beauty and durability but also for their symbolic and metaphysical properties. These beliefs have been passed down through generations and continue to influence the popularity of these gemstones in modern times.
Turquoise
Turquoise is often associated with protection, healing, and spiritual connection. It is believed to bring calmness and tranquility to the wearer and is often used in meditation and spiritual practices. In ancient cultures, turquoise was thought to protect the wearer from harm and bring good fortune.
In Native American traditions, turquoise is considered a sacred stone and is used in ceremonial regalia. It is also believed to have healing properties, particularly for the lungs and respiratory system. Some modern sources also suggest that turquoise can help with detoxification and immune support, though this is not widely accepted in formal gemology.
Tanzanite
Tanzanite is associated with transformation, growth, and spiritual awakening. It is believed to help the wearer embrace change and step into new chapters of life with clarity and confidence. Its deep blue-violet color is thought to stimulate the third eye chakra, enhancing intuition and insight.
Tanzanite is also considered a stone of compassion and is believed to help the wearer develop empathy and understanding. It is often used in healing practices and is thought to promote emotional balance and harmony.
Blue Zircon
Blue zircon is associated with clarity, wisdom, and balance. It is believed to help the wearer sharpen their focus and make clear, wise decisions. It is also thought to enhance mental clarity and emotional stability, making it a popular choice for those seeking inner peace and balance.
In some traditions, blue zircon is believed to attract wealth and prosperity. It is also considered a stone of protection, helping the wearer stay grounded and focused in times of stress or uncertainty.
Blue Topaz
Blue topaz is associated with calmness, serenity, and emotional balance. It is believed to help the wearer manage stress and anxiety and promote a sense of inner peace. It is also thought to enhance communication and expression, making it a popular choice for those who want to speak their truth and express themselves clearly.
In some traditions, blue topaz is believed to enhance sleep and promote restful, dream-filled rest. It is also considered a stone of love and affection, helping to strengthen emotional bonds and relationships.
Care and Cleaning
Proper care and cleaning are essential for maintaining the beauty and longevity of December birthstone jewelry. Each gemstone has unique properties that require specific care instructions.
Turquoise
- Avoid exposure to water and moisture, as it can cause the stone to degrade or change color.
- Store in a dry, cool place to prevent damage.
- Clean with a soft cloth and mild soap, but avoid prolonged soaking.
- Avoid contact with chemicals and abrasives, as they can damage the surface of the stone.
Tanzanite
- Avoid exposure to heat and direct sunlight, as it can cause the stone to fade or lose its color.
- Store in a soft cloth or jewelry box to prevent scratches.
- Clean with a soft cloth and mild soap, avoiding harsh chemicals and ultrasonic cleaners.
- Avoid exposure to physical shock, as it can cause the stone to chip or break due to its perfect cleavage.
Blue Zircon
- Avoid exposure to heat and direct sunlight, as it can cause the stone to fade or lose its color.
- Store in a soft cloth or jewelry box to prevent scratches.
- Clean with a soft cloth and mild soap, avoiding harsh chemicals and ultrasonic cleaners.
- Avoid exposure to physical shock, as it can cause the stone to chip or break.
Blue Topaz
- Avoid exposure to heat and direct sunlight, as it can cause the stone to fade or lose its color.
- Store in a soft cloth or jewelry box to prevent scratches.
- Clean with a soft cloth and mild soap, avoiding harsh chemicals and ultrasonic cleaners.
- Avoid exposure to physical shock, as it can cause the stone to chip or break.
Conclusion
December is a month of winter wonder, holiday cheer, and a unique distinction in the world of gemstones: it is the only month with four officially recognized birthstones. These include tanzanite, turquoise, blue zircon, and blue topaz. Each of these gemstones carries its own rich history, distinct gemological properties, and symbolic meaning, making them ideal choices for jewelry and personal adornment.
Turquoise has a long and storied history, with roots in ancient Egypt and other cultures. It is known for its calming blue-green color and its association with protection, healing, and spiritual connection.
Tanzanite, discovered in Tanzania in 1967, is a rare gemstone with a deep blue-violet color. It is associated with transformation, growth, and spiritual awakening, and it was officially recognized as a December birthstone in 2002.
Blue Zircon is a high refractive index gemstone with a brilliant, diamond-like sparkle. It is often heat-treated to enhance its blue color and is associated with clarity, wisdom, and balance.
Blue Topaz is a relatively recent addition to the December birthstone list. It is known for its hardness and affordability, making it a popular choice for jewelry. It is associated with calmness, serenity, and emotional balance.
Each of these December birthstones has its own unique characteristics, making them a beautiful and meaningful choice for those born in December. Whether you are drawn to the calming blue-green hues of turquoise, the deep blue-violet tones of tanzanite, the brilliant sparkle of blue zircon, or the crisp winter blue of blue topaz, there is a December birthstone that is perfect for you.