December, the final month of the calendar year, is uniquely marked by having three birthstones: turquoise, tanzanite, and zircon—with blue zircon often singled out as a particularly popular variant. Each of these gemstones carries a distinct identity in terms of appearance, history, and symbolism, making December one of the most intriguing months in the birthstone calendar. From the ancient reverence of turquoise in Egyptian and Chinese cultures to the modern discovery of tanzanite in Tanzania and the geological antiquity of zircon, December’s birthstones offer a rich tapestry of color, meaning, and significance.
This article delves into the colors, properties, and cultural significance of these December birthstones, providing a comprehensive guide for gemstone enthusiasts, jewelry buyers, and those interested in the historical and symbolic legacy of December’s gems.
A Trio of December Birthstones
December is unique in the birthstone tradition for having three recognized birthstones—a rarity in the calendar. The current list includes turquoise, tanzanite, and zircon, each of which has a distinct color profile and a unique place in the history of gemology and cultural symbolism.
The inclusion of three birthstones for one month is a relatively modern phenomenon. In earlier times, December was associated with different gems. For example, ruby was considered a December birthstone in ancient biblical lists, and lapis lazuli was included in the early 20th century as an alternative to turquoise. The modern list has evolved through the efforts of various institutions, including the National Association of Jewellers (now Jewellers of America) and the Jewelry Industry Council of America, who have contributed to the inclusion and reclassification of these gems over time.
Why Blue?
While the December birthstones come in a range of colors, blue is the most prominent and unifying feature. This is not coincidental. December, with its association with cold weather, holiday gatherings, and celebrations of light, is a month often linked to the blue hues of twilight, winter skies, and the symbolic "winter blues." The December birthstones—especially tanzanite, turquoise, and blue zircon—embody this connection with their rich and varied shades of blue, making them fitting symbols for the month.
Historical and Cultural Significance
Turquoise: A Stone of Protection and Prosperity
Turquoise is perhaps the most ancient of the three December birthstones, with a history stretching back thousands of years. It has been cherished by ancient Egyptians, Chinese artisans, and Native American cultures for its striking blue-green color and its perceived protective properties.
In ancient Egypt, turquoise was used in jewelry and amulets and was believed to offer protection from danger and misfortune. It was also associated with health and vitality. The stone was often inlaid into headdresses, pendants, and ceremonial objects used by pharaohs and nobility.
In Hindu traditions, turquoise was thought to bring wealth and good fortune, particularly if seen after the new moon. From the 13th century onward, it was believed to protect the wearer from falls, especially while riding a horse. This belief was so strong that it was said the stone would break into pieces if a disaster was imminent.
In the United States, Native American tribes such as the Navajo, Zuni, and Pueblo have used turquoise in jewelry and ceremonial items for centuries. It is often set in silver and is considered a symbol of life, health, and good luck.
Tanzanite: A Modern Discovery with Ancient Symbolism
Tanzanite is a relatively new addition to the birthstone list, having been discovered in 1967 in Tanzania, after which it was named. Unlike turquoise and zircon, tanzanite does not have an extensive historical record in ancient cultures. However, it quickly gained popularity due to its striking blue-violet color and its rarity—as it is found only in Tanzania.
Tanzanite is often described as "velvety" in appearance and is associated with healing, self-transformation, and spiritual awakening. It is believed to activate the throat, third-eye, and crown chakras, aiding in psychic development and communication with higher dimensions.
In terms of cultural significance, tanzanite is often considered a symbol of change and new beginnings, making it particularly fitting for December, a month that marks the end of one year and the start of another.
Zircon: One of the Oldest Minerals on Earth
Zircon is not only one of the December birthstones but also one of the oldest known minerals on Earth, with some zircon crystals dating back over 4 billion years. The name "zircon" comes from the Arabic word zar gun, meaning "gold color," although zircon is best known today for its blue variety.
Zircon has a long history of use in jewelry and mysticism. It was believed to grant the wearer the ability to see into the future, relieve pain, and increase appetite. Travelers wore zircon for protection from injury and disease, and it was also thought to bring a warm welcome to guests and ensure peaceful sleep.
Blue zircon, in particular, has gained popularity in modern jewelry due to its deep blue color, which is achieved through heat treatment. It is often used as a more affordable alternative to blue topaz or sapphire, and it is highly valued for its sparkle and brilliance.
Geological Formation and Sources
Each of December’s birthstones has a unique geological profile and is found in specific locations around the world.
Turquoise
Turquoise is a phosphate mineral formed in the oxidized zones of copper deposits, often found in cave or arid environments. It is composed of copper and aluminum, with its blue-green color coming from the presence of copper ions.
The most famous sources of turquoise include:
- Iran (Persia) – Known for producing some of the finest turquoise in history.
- Egypt – Used by the ancient Egyptians for jewelry and ceremonial objects.
- China – Used by artisans for carvings and inlays over 3,000 years ago.
- United States – Particularly in New Mexico and Arizona, where turquoise is still mined and used in Native American jewelry.
Turquoise is often found with matrix veins, which are the remnants of the host rock in which it formed. These matrix patterns can enhance the stone’s aesthetic appeal and are highly valued in jewelry and decorative objects.
Tanzanite
Tanzanite is a trigonal mineral with the chemical formula Ca₂Al₃(SiO₄)₃(OH). It is a variety of zoisite that has been heat-treated to enhance its blue-violet color. The gemstone is only found in Tanzania, specifically in the Merelani Hills near Arusha, near the famous Mount Kilimanjaro.
Tanzanite forms in metamorphic rock under high pressure and temperature conditions. The presence of chromium and vanadium is responsible for its vibrant blue and violet colors. Due to its limited source and increasing rarity, tanzanite is considered a valuable and collectible gemstone.
Zircon
Zircon is a zirconium silicate mineral with the chemical formula ZrSiO₄. It is known for its high refractive index and dispersion, which gives it a sparkling, diamond-like appearance. Zircon is one of the oldest minerals on Earth, with some crystals found in Australia dating back over 4 billion years.
Blue zircon is the most popular variety, achieved through heat treatment of brown zircon. This variety is often used as a more affordable alternative to blue topaz and sapphire. Zircon is also found in many countries, including Thailand, Cambodia, Vietnam, Nigeria, and Australia.
Zircon is stable in light and chemicals, but heat-treated varieties may revert to their original brown color if exposed to prolonged light or heat. Therefore, it is best to avoid exposing zircon to extreme temperatures to preserve its color and appearance.
Gemological Properties
Understanding the physical and optical properties of December’s birthstones is essential for gemologists, jewelers, and collectors alike. Each gem has distinct hardness, color, and refractive properties that influence its use in jewelry and its durability.
Turquoise
- Hardness (Mohs scale): 5 to 6
- Color: Blue to green, often with matrix veins
- Luster: Waxy or greasy
- Transparency: Opaque to translucent
- Refractive Index: 1.61 to 1.65
- Chemical Composition: Hydrated copper aluminum phosphate (CuAl₆(PO₄)₄(OH)₈·4H₂O)
- Durability: Moderate to low; prone to cracking and staining if exposed to acids or excessive moisture
Turquoise is relatively soft compared to other gemstones, which means it requires careful handling and cleaning. It is best suited for pendants, earrings, and brooches rather than rings or bracelets, where it may be more likely to crack or chip.
Tanzanite
- Hardness (Mohs scale): 6 to 7
- Color: Blue to violet, often with trichroism (displaying three different colors depending on the viewing angle)
- Luster: Vitreous (glassy)
- Transparency: Transparent to translucent
- Refractive Index: 1.69 to 1.70
- Chemical Composition: Calcium aluminum silicate hydroxide (Ca₂Al₃(SiO₄)₃(OH))
- Durability: Moderate; susceptible to scratching and chipping if not handled carefully
Tanzanite is prized for its intense color and brilliance, but its relatively moderate hardness means it is best suited for jewelry that is not worn daily. It is often used in pendants, earrings, and brooches.
Zircon
- Hardness (Mohs scale): 6 to 7.5
- Color: Blue (most common), colorless, yellow, red, orange
- Luster: Vitreous (glassy)
- Transparency: Transparent to translucent
- Refractive Index: 1.92 to 2.01 (very high)
- Chemical Composition: Zirconium silicate (ZrSiO₄)
- Durability: Moderate to high; can be brittle if treated
Zircon is known for its high refractive index and dispersion, which gives it a sparkling, diamond-like appearance. The blue variety is the most popular and is often confused with blue topaz or sapphire due to its deep blue color.
Zircon is stable in light and chemicals, but heat-treated varieties may lose their blue color over time. It is best to avoid exposing zircon to prolonged light or heat to preserve its color and appearance.
Symbolism and Metaphysical Beliefs
Each of December’s birthstones carries symbolic and metaphysical meanings that have been passed down through history and continue to influence modern gemstone practices.
Turquoise
Turquoise has long been associated with protection, health, and good fortune. In ancient Egypt, it was believed to ward off illness and misfortune, and in Hindu traditions, it was thought to bring wealth and prosperity.
In Native American cultures, turquoise is a powerful symbol of life, health, and spiritual connection. It is often used in ceremonial jewelry and is believed to enhance intuition and communication.
In modern metaphysical beliefs, turquoise is associated with emotional healing, calmness, and self-expression. It is believed to soothe the mind and promote emotional balance, making it a popular choice for meditation and spiritual practices.
Tanzanite
Tanzanite is associated with spiritual growth, transformation, and emotional healing. It is believed to activate the throat, third-eye, and crown chakras, aiding in psychic development and communication with higher dimensions.
Tanzanite is also associated with self-reflection, inner peace, and emotional balance. It is said to help individuals release old patterns and embrace new beginnings, making it a particularly fitting gemstone for the end of the year.
Zircon
Zircon has a long history of spiritual and mystical associations. It was believed to grant the wearer the ability to see into the future, relieve pain, and increase appetite. Travelers wore zircon for protection from injury and disease, and it was also thought to bring a warm welcome to guests and ensure peaceful sleep.
In modern metaphysical practices, zircon is associated with mental clarity, emotional healing, and spiritual protection. It is believed to enhance intuition and psychic abilities and to promote a sense of calm and balance.
Care and Cleaning
Proper care and cleaning are essential for maintaining the beauty and longevity of December’s birthstones. Each gem has specific needs based on its hardness, color stability, and sensitivity to light and chemicals.
Turquoise
- Hardness: 5 to 6
- Care Tips: Avoid exposure to moisture, acids, and abrasives
- Cleaning: Gently clean with warm water and mild soap using a soft brush
- Avoid: Ultrasonic and steam cleaners, which can damage the stone
- Storage: Store separately from other stones to avoid scratching and staining
Tanzanite
- Hardness: 6 to 7
- Care Tips: Avoid exposure to high heat, ultraviolet light, and physical impact
- Cleaning: Clean with warm water and mild soap using a soft brush
- Avoid: Ultrasonic and steam cleaners, which can cause cracking or color fading
- Storage: Store in a cool, dark place to prevent color loss
Zircon
- Hardness: 6 to 7.5
- Care Tips: Avoid prolonged exposure to bright light or heat, which can fade the color
- Cleaning: Clean with warm water and mild soap using a soft brush
- Avoid: Ultrasonic and steam cleaners, which may damage heat-treated varieties
- Storage: Store separately from other stones to avoid scratching
Conclusion
December’s birthstones—turquoise, tanzanite, and zircon—offer a rich diversity of color, history, and symbolism. Each gemstone has its own unique properties and cultural significance, making them meaningful choices for jewelry and gifts.
Turquoise, with its deep blue-green hues and ancient origins, is a stone of protection and prosperity. Tanzanite, a modern discovery from Tanzania, is associated with spiritual growth and transformation. Zircon, one of the oldest minerals on Earth, is known for its sparkling brilliance and mystical properties.
Whether you choose a classic turquoise pendant, a vibrant tanzanite ring, or a sparkling blue zircon earrings, you are selecting a gemstone that carries centuries of history and meaning. As the final month of the year, December is a time of reflection, celebration, and new beginnings, and its birthstones serve as beautiful reminders of these themes.