The December 21 birthstone is a unique designation that highlights the rich gemological and cultural significance of three distinct gemstones: Tanzanite, Turquoise, and Zircon. While each of these stones holds its own allure and symbolic meaning, they all share a common birthstone color—blue. This article explores the properties, history, cultural significance, and practical care of these December 21 birthstones, drawing from authoritative sources that provide a detailed and nuanced perspective.
From the ancient origins of Turquoise in early human civilizations to the modern discovery of Tanzanite in the 1960s, the story of these gemstones is one of rarity, transformation, and enduring beauty. This article will cover their geological formation, symbolic meanings, and their roles in jewelry and personal adornment. We will also examine how these stones are used in contemporary jewelry design and how to best care for them.
History and Lore
Ancient Roots of Turquoise
Turquoise is one of the oldest known gemstones, with a history that stretches back thousands of years. It was formed through a process involving groundwater rich in copper seeping into the bedrock, where it reacted with other minerals over time to form the opaque stone known for its stunning shades of blue and green. The dark lines and shapes seen in turquoise are derived from the surrounding rock, known as matrix. This gemstone has been cherished since ancient times and is one of the earliest to be used in jewelry.
In ancient Egypt, Turquoise was highly valued and used in elaborate jewelry by pharaohs and other rulers. It was also used by Chinese artisans over 3,000 years ago, who carved intricate pieces from the stone. The turquoise birthstone was believed to possess many beneficial powers, such as guaranteeing health and good fortune. From the 13th century onward, it was also believed to protect the wearer from falling, especially off horses, and would break into pieces at the approach of disaster.
Hindu mystics even held the belief that seeing a turquoise after beholding the new moon would ensure fantastic wealth. These beliefs underscore the deep cultural and spiritual significance of Turquoise across different civilizations.
The Modern Discovery of Tanzanite
In contrast to the ancient history of Turquoise, Tanzanite is a relatively new gemstone. Discovered in the 1960s in northern Tanzania, Tanzanite is a rare violet-blue gemstone that is found only in a small geographical area around Mount Kilimanjaro. This unique origin makes it one of the rarest gemstones in the world. Tanzanite is a type of zoisite that is typically faceted into a variety of shapes and exhibits a strong pleochroism, meaning it can display different colors—ranging from blue to purple—depending on the viewing angle and lighting conditions.
Tanzanite was first marketed by Tiffany & Co., which helped establish its popularity in the jewelry industry. Its vibrant colors and rarity quickly made it a favorite among collectors and jewelry enthusiasts. Due to its strong pleochroism, Tanzanite is often heat-treated to enhance its coloration, ensuring that the most desirable blue and purple hues are displayed when the gem is cut and polished.
Zircon: A Timeless Sparkle
Zircon, another of December's birthstones, has been used in jewelry for over 2000 years. Known for its brilliant sparkle, Zircon is available in a wide range of colors, though blue Zircon is the most popular variety associated with December. This gemstone is valued for its clarity and fire, which can rival that of diamonds and other high-value gems. Zircon is also known for its historical use in ancient civilizations and its continued popularity in modern jewelry design.
The use of Zircon in jewelry dates back to the early civilizations of the Middle East and Asia, where it was prized for its beauty and durability. Today, Zircon continues to be a popular choice for both fine and costume jewelry due to its affordability and aesthetic appeal.
Geological Formation and Sources
Turquoise Formation
Turquoise is formed through a process involving groundwater containing copper seeping into the bedrock, where it reacts with other minerals over time. This reaction results in the formation of an opaque stone with stunning shades of blue and green. The matrix, or the surrounding rock, contributes to the unique patterns and coloration of each piece of turquoise. The presence of phosphorus and aluminum in the stone is essential to its formation.
Historically, turquoise was mined in various parts of the world, including Iran, China, and the American Southwest. However, the most famous source of turquoise today is the Nevada region in the United States, where it is still mined and used in Native American jewelry.
Tanzanite Formation
Tanzanite, a type of zoisite, is formed under high pressure and temperature conditions in the crust of the Earth. The unique geological conditions around Mount Kilimanjaro in Tanzania have allowed for the formation of this rare gemstone. The mineral structure of Tanzanite is such that it exhibits a strong pleochroism, meaning it can display different colors depending on the angle and light source.
The discovery of Tanzanite in the 1960s was a significant event in the gemstone world. The stone's rarity and vibrant colors quickly made it a popular choice for jewelry. Due to the limited geographical source of Tanzanite, it is considered one of the most exclusive gemstones in the world.
Zircon Formation
Zircon is a metamorphic mineral that forms in a variety of geological settings, including granite and metamorphic rocks. The formation of Zircon involves the crystallization of zirconium silicate under high temperature and pressure. The most popular variety of Zircon associated with December is blue Zircon, which is typically heat-treated to enhance its color and clarity.
Zircon is found in many parts of the world, including Australia, India, and Brazil. Its widespread distribution has made it a popular and affordable gemstone, especially in the form of blue Zircon used in jewelry. The historical use of Zircon in jewelry dates back to ancient times, and it continues to be a favorite in both fine and costume jewelry.
Gemological Properties
| Gemstone | Color | Hardness (Mohs) | Composition | Transparency | Refractive Index | Treatments | Origin |
|---|---|---|---|---|---|---|---|
| Turquoise | Blue to green | 5–6 | Phosphate mineral | Opaque | 1.61–1.65 | None | Nevada, USA |
| Tanzanite | Blue to purple | 6–7 | Zoisite | Transparent | 1.69–1.70 | Heat | Tanzania |
| Zircon | Blue | 6–7.5 | Zirconium silicate | Transparent | 1.92–2.00 | Heat | Australia, India |
Turquoise Properties
Turquoise is an opaque gemstone with a hardness of 5–6 on the Mohs scale, making it relatively soft and easily scratched. Its composition includes phosphorus and aluminum, which contribute to its distinctive blue to green coloration. Turquoise is often set in jewelry using silver or gold, as these metals provide good support and protection for the stone.
Due to its softness, Turquoise requires special care to avoid scratching or cracking. It is best stored separately from harder gemstones and should be cleaned with a soft cloth and mild detergent. Avoid exposing it to harsh chemicals or excessive heat, as these can damage the stone's surface.
Tanzanite Properties
Tanzanite is a transparent gemstone with a hardness of 6–7 on the Mohs scale, making it relatively durable but still susceptible to scratching. Its composition is zoisite, a mineral that is known for its pleochroism, which allows the gem to display different colors depending on the viewing angle and lighting conditions.
Tanzanite is typically heat-treated to enhance its coloration, ensuring that the most desirable blue and purple hues are displayed when the gem is cut and polished. This treatment is stable and does not affect the gem's durability or clarity. Tanzanite is best set in precious metals like white gold or platinum, which provide good support and protection for the stone.
Zircon Properties
Zircon is a transparent gemstone with a hardness of 6–7.5 on the Mohs scale, making it relatively durable and suitable for everyday wear. Its composition is zirconium silicate, a mineral known for its brilliance and fire, which can rival that of diamonds and other high-value gems.
The most popular variety of Zircon associated with December is blue Zircon, which is typically heat-treated to enhance its color and clarity. This treatment is stable and does not affect the gem's durability or clarity. Zircon is best set in precious metals like white gold or platinum, which provide good support and protection for the stone.
Symbolism and Metaphysical Beliefs
Turquoise: A Stone of Protection and Healing
Turquoise has long been associated with protection, healing, and good fortune. In ancient Egypt, it was used to adorn pharaohs and other rulers, symbolizing divine power and protection. In Chinese culture, turquoise was believed to bring longevity and prosperity, and it was used in intricate carvings and jewelry.
In Native American cultures, turquoise is considered a sacred stone that is used in ceremonies and rituals. It is believed to bring good luck, health, and spiritual protection. In many Native American tribes, turquoise is used in healing ceremonies and is considered a stone of the sky and water, symbolizing clarity, calm, and spiritual connection.
Tanzanite: A Stone of Transformation and Intuition
Tanzanite is believed to have metaphysical properties that support transformation, intuition, and emotional healing. Due to its rare and unique origin, it is considered a stone of change and personal growth. Tanzanite is often used in spiritual practices to enhance emotional balance and intuition, helping individuals connect with their inner wisdom and higher self.
In some cultures, Tanzanite is also associated with karmic healing, helping individuals release negative patterns and emotions. It is believed to promote clarity and insight, making it a valuable tool for spiritual exploration and self-discovery.
Zircon: A Stone of Energy and Clarity
Zircon is believed to have energetic properties that enhance clarity, focus, and spiritual awareness. In ancient times, it was used in protective amulets and talismans, believed to ward off evil spirits and negative energies. Zircon is also associated with healing and vitality, and it is believed to promote physical and mental well-being.
In some cultures, Zircon is considered a stone of the sun, symbolizing light, energy, and transformation. It is often used in spiritual practices to enhance clarity and insight, helping individuals connect with their inner wisdom and higher self.
Care and Cleaning
Turquoise Care
Turquoise is a soft gemstone with a hardness of 5–6 on the Mohs scale, making it susceptible to scratches and damage. It is best stored separately from other gemstones to avoid scratching or chipping. When cleaning Turquoise, it is important to use a soft cloth and mild detergent, avoiding harsh chemicals or abrasive materials.
Turquoise should also be protected from excessive heat and direct sunlight, as these can cause color fading and dehydration. It is best to store Turquoise in a cool, dry place, away from extreme temperatures and humidity.
Tanzanite Care
Tanzanite is a relatively durable gemstone with a hardness of 6–7 on the Mohs scale, making it suitable for everyday wear. However, it is still susceptible to scratching and chipping, especially along cleavage planes. Tanzanite should be stored separately from harder gemstones to avoid damage and scratching.
When cleaning Tanzanite, it is best to use a soft cloth and mild detergent, avoiding harsh chemicals or ultrasonic cleaners, which can damage the gemstone's surface. Tanzanite should also be protected from extreme heat and direct sunlight, as these can cause color fading and damage.
Zircon Care
Zircon is a durable gemstone with a hardness of 6–7.5 on the Mohs scale, making it suitable for everyday wear. However, it is still susceptible to scratching and chipping, especially along cleavage planes. Zircon should be stored separately from other gemstones to avoid damage and scratching.
When cleaning Zircon, it is best to use a soft cloth and mild detergent, avoiding harsh chemicals or ultrasonic cleaners, which can damage the gemstone's surface. Zircon should also be protected from extreme heat and direct sunlight, as these can cause color fading and damage.
Conclusion
The December 21 birthstone is a unique designation that highlights the rich gemological and cultural significance of Tanzanite, Turquoise, and Zircon. These gemstones, all associated with the color blue, share a common thread of beauty, rarity, and symbolism that has captivated people for centuries.
From the ancient history of Turquoise, used by pharaohs and mystics alike, to the modern discovery of Tanzanite, which continues to amaze with its vibrant colors and rarity, and the enduring sparkle of Zircon, which has been cherished for over 2000 years, these gemstones represent a convergence of history, science, and culture.
Whether used in fine jewelry, spiritual practices, or personal adornment, these December 21 birthstones continue to inspire and captivate. Their unique properties, historical significance, and symbolic meanings make them treasured gems that are sure to be cherished for generations to come.