December, the final month of the year, is distinguished not only by its cold weather and festive traditions but also by its unique status in the world of gemstones. Unlike most other months, December is associated with four officially recognized birthstones: Turquoise, Tanzanite, 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. This article provides an in-depth exploration of the December birthstones, drawing from historical, geological, and cultural sources to present a comprehensive overview.
Introduction
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 birthstones have undergone several changes, reflecting both the evolving nature of the tradition and the discovery of new gemstones. Originally, only Turquoise and Zircon were considered December's gemstones. However, in the 20th century, the list expanded to include Blue Topaz and Tanzanite, the latter being added in 2002.
This expansion reflects the growing appreciation for new gemstone discoveries and their commercial appeal. The four December birthstones are all characterized by their blue hues, a nod to the cool tones of winter and the calmness associated with the season. Each of these gemstones has its own unique story, from ancient lore to modern symbolism, and each offers distinct properties that influence their use in jewelry and personal adornment.
History and Lore
Ancient Origins of Birthstone Traditions
The concept of assigning gemstones to specific months or zodiac signs is believed to have its roots in ancient Mesopotamia, where gemstones were thought to possess mystical powers and were associated with the twelve tribes of Israel. This tradition was later adopted and adapted by the ancient Greeks and Romans, who expanded the idea to include gemstones associated with the zodiac signs.
By the 18th and 19th centuries, the tradition had been standardized in various parts of the world, with Europe and North America developing their own interpretations. In the United States, the National Association of Jewelers played a key role in standardizing the list of birthstones in 1912, combining traditional customs with gemstones that were practical for jewelry makers.
The Evolution of December's Birthstones
In the early 20th century, Turquoise and Zircon were the primary gemstones associated with December. However, as new gemstones were discovered and gained popularity, the list expanded. Blue Topaz was added in the mid-20th century, and Tanzanite was officially recognized in 2002. This expansion reflects both the commercial interests of the jewelry industry and the growing appreciation for new gemstone discoveries.
Tanzanite, in particular, is notable for its rarity and vibrant violet-blue color, which has made it a popular choice for high-end jewelry. Its limited availability—being mined only in a specific region of Tanzania—adds to its allure and value.
Geological Formation and Sources
Turquoise
Turquoise is a phosphorus-based mineral that forms in the oxidized zones of copper deposits. It is typically found in arid climates, where it is formed through the interaction of copper and aluminum with phosphoric acid, often derived from organic matter or guano.
Major sources of turquoise include:
- United States: particularly Arizona, New Mexico, and Nevada
- Nigeria
- China
- Iran
- Mongolia
Turquoise is often found in matrix, meaning it is embedded within the surrounding rock. This matrix can vary in color and pattern, affecting the appearance and value of the stone.
Tanzanite
Tanzanite is a trigonal mineral and a variety of the gemstone zoisite. It is known for its rich blue-violet color, which is caused by the presence of vanes in the crystal structure that absorb certain wavelengths of light.
Tanzanite is exclusively found in Tanzania, specifically in the Merelani Hills of the Shinyanga region. It was discovered in 1967 and has since become one of the most sought-after gemstones in the world. Due to its limited geographic source, tanzanite is considered rare and valuable.
Zircon
Zircon is a zirconium silicate mineral that occurs in a wide variety of colors, including blue, brown, yellow, green, and red. The blue zircon used as a birthstone is typically heat-treated to enhance its color.
Zircon is found in many parts of the world, including:
- Sri Lanka
- Madagascar
- Australia
- Burmah (Myanmar)
- India
- Brazil
Blue zircon is particularly valued for its high refractive index, which gives it a sparkling appearance. It is also relatively durable, making it a good choice for everyday jewelry.
Blue Topaz
Topaz is a silicate mineral composed of aluminum and fluorine, with a hexagonal crystal structure. The blue color in blue topaz is the result of irradiation and heat treatment, which alters the chemical structure of the stone and gives it its characteristic blue hue.
Blue topaz is found in several countries, including:
- Sri Lanka
- Brazil
- Mexico
- Nigeria
- United States (specifically Texas, where it is the official state gem)
It is one of the hardest December birthstones, with a Mohs hardness of 8, making it highly durable and suitable for everyday wear.
Gemological Properties
| Gemstone | Color | Hardness (Mohs Scale) | Chemical Formula | Refractive Index | Transparency | Cut | Market Value |
|---|---|---|---|---|---|---|---|
| Turquoise | Blue, blue-green | 5–6 | CuAl₆(PO₄)₄(OH)₈·4H₂O | 1.61–1.65 | Opaque to Translucent | Cabochon | Medium to High |
| Tanzanite | Blue-violet | 6–7 | Ca₂Al₃(SiO₄)₃(OH) | 1.694–1.701 | Transparent | Faceted | High |
| Zircon | Blue | 6–7.5 | ZrSiO₄ | 1.92–2.01 | Transparent | Faceted | Medium |
| Blue Topaz | Blue | 8 | Al₂SiO₄(F,OH)₂ | 1.61–1.62 | Transparent | Faceted | Low to Medium |
Turquoise
- Hardness: 5–6 on the Mohs scale, making it relatively soft and susceptible to scratches.
- Color: Ranges from sky blue to greenish-blue, often with matrix patterns.
- Transparency: Typically opaque or translucent.
- Cut: Usually cut as a cabochon to highlight its color and patterns.
Tanzanite
- Hardness: 6–7 on the Mohs scale.
- Color: Deep blue-violet, with pleochroism, meaning it can display different colors when viewed from different angles.
- Transparency: Transparent, with high luster.
- Cut: Typically faceted to enhance its sparkle and color.
Zircon
- Hardness: 6–7.5 on the Mohs scale.
- Color: Blue zircon is the most common birthstone color for December.
- Transparency: Transparent, with a high refractive index, giving it a sparkling appearance.
- Cut: Usually faceted to showcase its brilliance.
Blue Topaz
- Hardness: 8 on the Mohs scale, making it the hardest December birthstone.
- Color: Vibrant blue, achieved through irradiation and heat treatment.
- Transparency: Transparent, with a clear, glassy appearance.
- Cut: Typically faceted, with brilliant cuts that enhance its sparkle.
Symbolism and Metaphysical Beliefs
Turquoise
Turquoise has been revered for thousands of years across various cultures. In ancient Egypt, it was used in jewelry and amulets, believed to bring protection and good fortune. In Native American cultures, it is considered a sacred stone, symbolizing healing, protection, and spiritual communication.
Modern metaphysical beliefs associate turquoise with calmness, clarity, and emotional balance. It is often used to soothe anxiety, enhance communication, and promote inner peace.
Tanzanite
Tanzanite is a modern gemstone with symbolic associations that reflect its vibrant color and rarity. It is often linked to transformation, growth, and new beginnings. Its blue-violet hue is said to represent clarity, intuition, and spiritual insight.
In New Age metaphysics, tanzanite is believed to activate the third eye chakra, enhancing spiritual awareness and emotional healing.
Zircon
Zircon has been used in jewelry for centuries, particularly in ancient civilizations like Egypt and Mesopotamia. It was once mistaken for zirconium due to its sparkling appearance, and it was even classified as a type of diamond in the past.
In modern metaphysical practices, blue zircon is associated with mental clarity, focus, and spiritual awakening. It is believed to enhance cognitive function, stimulate creativity, and promote emotional balance.
Blue Topaz
Blue topaz is often associated with calmness and serenity. It is believed to soothe the mind, reduce stress, and enhance emotional stability. In metaphysical traditions, blue topaz is also thought to enhance intuition, promote honesty, and encourage truthfulness.
It is a popular choice for engagement rings, as it is durable and affordable, and it carries positive symbolism related to love, clarity, and emotional strength.
Care and Cleaning
Proper care is essential for maintaining the beauty and longevity of December birthstone jewelry. Each gemstone has specific care requirements based on its hardness, chemical composition, and sensitivity to heat and light.
Turquoise
- Hardness: 5–6, so it is relatively soft and prone to scratches.
- Moisture Sensitivity: Turquoise is hygroscopic, meaning it absorbs moisture and can fog or dull if exposed to water or excessive humidity.
- Cleaning: Use a soft cloth and warm, soapy water. Avoid ultrasonic cleaners and steam cleaning, as they can damage the stone.
Tanzanite
- Hardness: 6–7, making it moderately durable.
- Light Sensitivity: Tanzanite can fade when exposed to prolonged sunlight, so it should be stored in a dark place.
- Cleaning: Use a soft cloth and warm, soapy water. Avoid chemicals and abrasive cleaners, as they can damage the surface.
Zircon
- Hardness: 6–7.5, making it fairly durable.
- Heat Sensitivity: Zircon can lose its color if exposed to high heat, so it should be avoided in high-temperature settings.
- Cleaning: Use a soft cloth and warm, soapy water. Avoid abrasive cleaners, as they can scratch the surface.
Blue Topaz
- Hardness: 8, making it the hardest December birthstone.
- Durability: Blue topaz is very durable and suitable for everyday wear.
- Cleaning: Use a soft cloth and warm, soapy water. It is safe to use ultrasonic cleaners, but avoid steam cleaning if the stone has undergone irradiation.
Conclusion
December is a month of cold weather, holiday cheer, and a unique distinction in the world of gemstones. It is the only month with four officially recognized birthstones: Turquoise, Tanzanite, 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.
From the ancient origins of the birthstone tradition to the modern-day discoveries of Tanzanite and Blue Topaz, the December birthstones reflect the evolving nature of the tradition and the appreciation for new gemstone discoveries. Their blue hues are a nod to the cool tones of winter, while their unique properties and symbolism offer something for every personality and style.
Whether you are a gemstone enthusiast, a jewelry buyer, or a student of gemology, the December birthstones offer a fascinating study in history, science, and culture. Their beauty and significance continue to capture the imagination and spark the interest of gem lovers around the world.