December 20th is one of the few dates in the calendar year that is associated with multiple birthstones: turquoise, tanzanite, and zircon. Each of these gemstones carries its own unique history, symbolism, and gemological properties, making the December 20th birthstone selection particularly rich and diverse. This article explores the three gemstones designated for December 20th, delving into their geological origins, cultural significance, and the qualities attributed to them across various traditions and eras. By examining the interplay of scientific data and historical lore, we gain a deeper appreciation of why these stones continue to captivate gemstone enthusiasts and jewelry lovers alike.
The Historical and Cultural Significance of December 20th Birthstones
The selection of birthstones for specific dates is a tradition that dates back centuries, with roots in ancient biblical and mythological texts. Over time, the list of birthstones has evolved, with various organizations and cultural groups adding or modifying the stones associated with each month. For December, the inclusion of three birthstones—turquoise, tanzanite, and zircon—reflects the dynamic nature of this tradition and the diverse cultural and geographical influences that have shaped it.
Turquoise: The Ancient Gem of Transformation
Turquoise is one of the oldest known gemstones, with evidence of its use dating back over 6,000 years. It has been found in archaeological sites across the Middle East, Egypt, and the Americas. In ancient times, turquoise was highly valued for its vibrant blue-green color and its perceived spiritual and protective properties. It was often used in religious ceremonies, as a protective amulet, and as a symbol of divine favor. In many cultures, turquoise was believed to promote wisdom, calmness, and communication.
As the primary birthstone for December, turquoise holds a special place for those born on the 20th. Its deep blue hues and chatoyant surface make it a visually striking gem, while its historical significance and enduring beauty add to its appeal. Turquoise has also been associated with the concept of transformation and personal growth, making it a meaningful stone for individuals seeking clarity and renewal in their lives.
Tanzanite: The Modern Marvel from Tanzania
Tanzanite, a relatively recent discovery in the world of gemology, was first identified in Tanzania in 1967. This deep blue to violet gemstone is unique in that it is found only in one location in the world, making it one of the rarest gemstones. Tanzanite is often included in the December birthstone list due to its striking color and its association with emotional healing and spiritual awakening.
The discovery of tanzanite was a significant event in the gemstone world, as it introduced a new gemstone with both scientific and aesthetic appeal. Its color is caused by the presence of vanadium, and it is known for its pleochroism—meaning it can display different colors depending on the angle at which it is viewed. This characteristic adds to the allure of tanzanite, making it a popular choice for jewelry and personal adornment.
Zircon: A Timeless Gemstone with Ancient Roots
Zircon is another gemstone that has a long and storied history, with examples of its use found in ancient civilizations across the globe. The name "zircon" comes from the Arabic word "zarkun," which means "gold-like," a reference to the gemstone’s fiery brilliance. Zircon can occur in a variety of colors, including blue, yellow, green, and red, with the blue variety being the most popular for jewelry.
Zircon is often included as a December birthstone, particularly in the form of blue zircon, which is known for its clarity and vibrancy. Its historical use as a gemstone in ancient times, combined with its modern appeal, makes zircon a versatile and meaningful choice for those born on December 20th. In addition to its beauty, zircon is believed to promote positive energy and emotional balance, aligning with the themes of renewal and transformation associated with the December season.
Geological Formation and Sources of December 20th Birthstones
Understanding the geological formation and sources of a gemstone provides valuable insight into its rarity, value, and unique characteristics. For the December 20th birthstones—turquoise, tanzanite, and zircon—each gemstone has a distinct formation process and geographic origin that contributes to its allure and significance.
Turquoise: A Product of Earth and Time
Turquoise is a hydrated phosphate of aluminum and copper, with the chemical formula CuAl₆(PO₄)₄(OH)₈·4H₂O. It forms in the oxidized zones of copper deposits, where water-rich solutions interact with surrounding minerals. The presence of copper gives turquoise its characteristic blue color, while the presence of iron can lead to a greenish hue. The gemstone is often found in association with other minerals such as quartz, calcite, and halite.
The most significant sources of turquoise are in the United States, particularly in Arizona and New Mexico. Other notable sources include Iran, China, and Egypt. The quality and color of turquoise can vary depending on the specific location of the deposit, with some of the most highly prized turquoise coming from the Sleeping Beauty Mine in Arizona. This turquoise is known for its even blue color and minimal matrix (the surrounding rock that can contain veins of black or brown).
Tanzanite: A Unique Geological Phenomenon
Tanzanite is a variety of the mineral zoisite, with the chemical formula Ca₂Al₃(SiO₄)(OH)₃·(OH). Its deep blue to violet color is caused by the presence of vanadium, a rare element that is responsible for the gemstone’s striking hue. Tanzanite is only found in one location in the world: the Merelani Hills in northern Tanzania. This area is part of the larger Tanga region, where tanzanite was first discovered in 1967.
The formation of tanzanite is a result of specific geological conditions, including the presence of vanadium-rich magma and the right combination of heat and pressure. These conditions are unique to the Merelani Hills, making tanzanite a gemstone of great rarity. The limited availability of tanzanite has contributed to its value and desirability, particularly among collectors and jewelry designers.
Zircon: A Versatile and Durable Gemstone
Zircon is a silicate mineral with the chemical formula ZrSiO₄. It occurs in a wide range of colors, including blue, yellow, green, and red, with the blue variety being the most commonly used in jewelry. The color variation in zircon is due to the presence of trace elements such as uranium and thorium, which can cause radioactive decay and lead to color changes in the gemstone.
Zircon is found in various parts of the world, including Australia, Sri Lanka, Myanmar, and the United States. The gemstone is known for its high refractive index and dispersion, which give it a fire and brilliance similar to that of diamonds. This makes zircon a popular choice for those seeking an affordable alternative to diamond in jewelry.
Gemological Properties of December 20th Birthstones
Each of the December 20th birthstones—turquoise, tanzanite, and zircon—has unique gemological properties that contribute to their beauty, durability, and value. Understanding these properties can help gemstone enthusiasts and jewelry buyers make informed decisions when selecting or caring for these gems.
Turquoise: A Soft and Delicate Gem
Turquoise has a hardness of 5 to 6 on the Mohs scale, which makes it relatively soft compared to other gemstones. This low hardness means that turquoise can be easily scratched or damaged, requiring careful handling and appropriate settings in jewelry. The gemstone is also porous and can absorb oils and chemicals, making it sensitive to heat and harsh environments.
Despite its softness, turquoise is prized for its beauty and has been used in jewelry for centuries. The gemstone is often set in silver or gold, with the metal providing protection and enhancing its appearance. Turquoise is also known for its chatoyancy, a visual effect that creates a cat’s-eye-like shimmer on the surface of the stone.
Tanzanite: A Vibrant and Radiant Gem
Tanzanite has a hardness of 6 to 7 on the Mohs scale, making it slightly more durable than turquoise. However, it is still a relatively soft gemstone and can be scratched by harder materials. Tanzanite is also sensitive to heat and light, which can cause fading or discoloration over time. To preserve its color and brilliance, tanzanite should be stored in a cool, dark place and cleaned carefully using mild soap and water.
The gemstone’s pleochroism is one of its most striking features, allowing it to display different colors when viewed from different angles. This characteristic makes tanzanite a popular choice for jewelry, as it adds depth and dimension to the gemstone. Tanzanite is often cut into cushion or oval shapes to enhance its color and brilliance.
Zircon: A Durable and Brilliant Gem
Zircon has a hardness of 6 to 7.5 on the Mohs scale, making it more durable than turquoise and tanzanite. It is also known for its high refractive index and dispersion, which give it a fire and brilliance similar to that of diamonds. This makes zircon an excellent choice for everyday jewelry, as it can withstand normal wear and tear without easily becoming damaged.
Zircon is also known for its versatility, as it can be found in a wide range of colors and can be treated to enhance its appearance. Heat treatment is commonly used to change the color of zircon, particularly to produce the popular blue variety. This treatment is stable and does not affect the gemstone’s durability or value.
Symbolism and Metaphysical Beliefs of December 20th Birthstones
In addition to their physical and gemological properties, the December 20th birthstones—turquoise, tanzanite, and zircon—have long been associated with various symbolic and metaphysical beliefs. These beliefs, rooted in ancient traditions and cultural practices, add to the richness of these gemstones and their significance as birthstones.
Turquoise: A Stone of Protection and Transformation
Turquoise has been used for centuries as a protective amulet and a symbol of transformation. In many cultures, turquoise is believed to promote wisdom, calmness, and communication, making it a valuable gemstone for those seeking emotional balance and personal growth. The stone is also associated with the throat chakra, which is linked to self-expression and authenticity.
In addition to its spiritual properties, turquoise is also believed to have healing properties, particularly for the respiratory system and the immune system. It is often used in crystal healing and meditation practices to promote inner peace and clarity of thought. The connection between turquoise and transformation makes it a fitting birthstone for those born on December 20th, a time of year that is often associated with renewal and change.
Tanzanite: A Stone of Emotional Healing and Spiritual Awakening
Tanzanite is believed to have powerful emotional and spiritual properties, making it a popular choice for those seeking emotional healing and spiritual awakening. The gemstone is associated with the heart chakra and is believed to promote compassion, forgiveness, and emotional balance. It is also believed to enhance intuition and spiritual awareness, helping individuals connect with their higher selves and the divine.
In addition to its emotional and spiritual properties, tanzanite is also believed to have protective qualities, shielding the wearer from negative energy and promoting a sense of inner peace. This makes it a valuable gemstone for those seeking to overcome emotional challenges and cultivate a deeper sense of self-awareness and personal growth.
Zircon: A Stone of Clarity and Positive Energy
Zircon is believed to promote clarity of thought and positive energy, making it a valuable gemstone for those seeking to enhance their mental and emotional well-being. The gemstone is associated with the third eye chakra, which is linked to intuition, insight, and spiritual perception. It is also believed to promote emotional balance and stability, helping individuals overcome anxiety and stress.
Zircon is also believed to have protective qualities, shielding the wearer from negative energy and promoting a sense of inner peace. This makes it a valuable gemstone for those seeking to cultivate a sense of calm and clarity in their lives. The versatility of zircon, combined with its beauty and durability, makes it a popular choice for both jewelry and spiritual practices.
Care and Cleaning of December 20th Birthstones
Proper care and cleaning are essential for maintaining the beauty and longevity of December 20th birthstones. Each of these gemstones—turquoise, tanzanite, and zircon—has specific care requirements that should be followed to ensure they remain in optimal condition.
Caring for Turquoise
Due to its softness and porosity, turquoise requires gentle care to avoid damage. It should be cleaned using mild soap and water, with a soft cloth or brush used to remove any dirt or debris. Avoid using harsh chemicals, ultrasonic cleaners, or steam cleaners, as these can cause the gemstone to fade or become damaged.
Turquoise should also be stored in a cool, dry place to prevent it from drying out or losing its color. It is important to avoid exposing turquoise to heat, direct sunlight, or harsh chemicals, as these can cause the gemstone to crack or discolor over time.
Caring for Tanzanite
Tanzanite should be cleaned using mild soap and water, with a soft cloth or brush used to remove any dirt or debris. Avoid using harsh chemicals, ultrasonic cleaners, or steam cleaners, as these can cause the gemstone to fade or become damaged.
Due to its sensitivity to heat and light, tanzanite should be stored in a cool, dark place to preserve its color and brilliance. It is also important to avoid exposing tanzanite to prolonged exposure to direct sunlight, as this can cause the gemstone to fade over time.
Caring for Zircon
Zircon is more durable than turquoise and tanzanite, making it easier to care for. It can be cleaned using mild soap and water, with a soft cloth or brush used to remove any dirt or debris. Zircon can also be cleaned using ultrasonic or steam cleaners, as these will not cause damage to the gemstone.
Zircon should be stored in a cool, dry place to prevent it from becoming scratched or damaged. It is also important to avoid exposing zircon to harsh chemicals, as these can cause the gemstone to become discolored or lose its brilliance over time.
Conclusion
The December 20th birthstones—turquoise, tanzanite, and zircon—each offer a unique combination of beauty, history, and symbolism that makes them a valuable addition to any gemstone collection or jewelry piece. From the ancient traditions surrounding turquoise to the modern marvel of tanzanite and the timeless appeal of zircon, these gemstones continue to captivate and inspire. Whether you are drawn to their physical properties, their historical significance, or their metaphysical qualities, the December 20th birthstones provide a rich and diverse selection that reflects the enduring fascination with gemstones and their role in human culture.