December, the final month of the calendar year, is celebrated not only for its festive traditions but also for its stunning array of birthstones. Unlike other months that are typically associated with a single gemstone, December boasts three official birthstones: Turquoise, Tanzanite, and Zircon, with Blue Topaz also recognized as an alternative. These stones are united by their captivating blue and blue-green hues, which reflect the serene and tranquil beauty of winter. Their colors and properties are deeply rooted in history, geology, and cultural symbolism, making them some of the most intriguing and versatile gemstones in the world.
This article explores the gemological, historical, and cultural significance of December’s birthstones. It delves into their formation, chemical composition, physical properties, and the reasons behind their association with the month of December. Additionally, it examines their roles in jewelry, their metaphysical attributes, and practical considerations for caring for these precious gems. By the end, you will understand why these stones are not only beautiful but also meaningful symbols of December’s unique character.
History and Lore
The tradition of associating gemstones with specific months dates back centuries, with roots in ancient civilizations that believed stones held protective and healing powers. December’s birthstones have a long and varied history, each with its own story and cultural significance.
Turquoise, the most well-known of December’s birthstones, has been prized for thousands of years. Its name comes from the French pierre turquoise, meaning “Turkish stone,” a reference to its introduction to Europe through Turkish merchants. While the earliest known use of turquoise dates back to ancient Egypt, where it was used in jewelry and amulets, the stone has also been found in artifacts from Mesoamerica, the Indus Valley, and the Middle East. Turquoise was often believed to bring protection, wisdom, and prosperity, and it was considered a sacred stone in many cultures.
Tanzanite, by contrast, is a relatively modern discovery. It was first identified in 1967 in the foothills of Mount Kilimanjaro in Tanzania. This gemstone quickly gained popularity due to its unique pleochroic properties—its ability to display different colors (blue, violet, and burgundy) depending on the angle of view. Tanzanite was named in honor of its country of origin, and it has since become a symbol of exclusivity and mystery.
Zircon, another of December’s official birthstones, has a much older history. Zircon has been found in archaeological sites dating back to ancient times and was often used in jewelry and decorative objects. The name “zircon” is derived from the Persian word zargun, meaning “gold-colored,” a reference to the yellow or orange varieties of the stone. However, the blue zircon used as a December birthstone is a result of heat treatment, a process that enhances its color and clarity.
Together, these gemstones form a rich tapestry of December’s heritage, connecting the past with the present through their enduring beauty and symbolism.
Geological Formation and Sources
Understanding the geological processes that create a gemstone is essential to appreciating its value and uniqueness. Each of December’s birthstones is formed under distinct conditions, resulting in their varied colors and physical properties.
Turquoise is a hydrated phosphate of aluminum and copper. It is typically formed when copper-rich groundwater reacts with phosphorus-bearing minerals in the surrounding rock. This process occurs in arid regions where the water evaporates quickly, allowing the minerals to crystallize. Turquoise is found in several countries, including the United States (especially in the Southwest), Iran, China, and Egypt. It is often mined in small deposits and is known for its porous, waxy texture and the presence of dark veins called matrix, which are remnants of the host rock.
Tanzanite, a variety of the mineral zoisite, is unique in that it is found only in Tanzania. It forms under high-pressure and high-temperature conditions in metamorphic rock. The pleochroism of tanzanite is a result of its crystal structure and the presence of trace amounts of vanadium and chromium. Tanzanite is mined in the Merelani Hills near Mount Kilimanjaro, and its limited availability contributes to its high value and desirability.
Zircon, a zirconium silicate mineral, is one of the oldest minerals on Earth, with some zircon crystals dating back over 4 billion years. It forms in igneous and metamorphic rocks and is often found in sedimentary deposits. Natural blue zircon is the result of heat treatment, which alters the stone’s color. Zircon is found in countries such as Cambodia, Sri Lanka, and Thailand, and it is known for its brilliance and refractive properties.
These gemstones are not only beautiful but also products of the Earth’s complex geological history. Their formation and distribution reflect the dynamic processes that shape our planet, making them truly natural treasures.
Gemological Properties
The gemological properties of a stone—its hardness, color, refractive index, and other characteristics—play a crucial role in its use and appeal. December’s birthstones vary in their physical attributes, but they share a common theme of vibrant blue and blue-green hues.
| Birthstone | Hardness on Mohs Scale | Specific Gravity | Refractive Index | Key Characteristics |
|---|---|---|---|---|
| Turquoise | 5-6 | 2.60–2.90 | 1.61–1.65 | Porous, waxy luster, often with matrix patterns |
| Tanzanite | 6.5–7 | 3.10–3.38 | 1.69–1.70 | Pleochroic (displays blue, violet, and burgundy), trichroic |
| Zircon | 6–7.5 | 3.90–4.73 | 1.93–1.98 | High refractive index, often heat-treated to enhance color |
Turquoise is relatively soft, with a hardness of 5–6 on the Mohs scale. Its porous nature makes it susceptible to damage from water and chemicals, so it requires special care. It has a waxy luster and is often found in a range of blue and green tones, with the presence of matrix patterns adding to its visual appeal.
Tanzanite is harder than turquoise, with a hardness of 6.5–7. Its pleochroic nature means that it can appear blue, violet, or burgundy depending on the viewing angle, a feature that makes it highly desirable for jewelry. Tanzanite has a relatively high specific gravity and a moderate refractive index, contributing to its brilliance and depth of color.
Zircon is one of the hardest of December’s birthstones, with a hardness of 6–7.5. It has a high refractive index, which gives it a bright, fiery luster. Zircon is often heat-treated to enhance its color, and the blue variety used as a December birthstone is particularly popular for its vivid color and clarity.
These gemological properties influence the way each stone is used in jewelry and how it is cared for. Understanding these characteristics helps in selecting and maintaining these beautiful gemstones.
Symbolism and Metaphysical Beliefs
The symbolism and metaphysical properties of gemstones have been a part of human culture for millennia. December’s birthstones are no exception, each carrying its own set of meanings and beliefs.
Turquoise has long been associated with protection, wisdom, and prosperity. In ancient cultures, it was often used in amulets and talismans to ward off evil and bring good fortune. It was also believed to promote healing and balance, and it was used in rituals and ceremonies. In modern times, turquoise is still associated with these qualities, and it is often worn as a protective stone.
Tanzanite is a relatively new gemstone in terms of its recognition, but it has quickly gained a reputation for its spiritual properties. It is believed to enhance intuition, promote emotional healing, and encourage spiritual growth. Tanzanite is also associated with transformation and change, making it a popular choice for those undergoing significant life transitions.
Zircon, especially the blue variety used as a December birthstone, is believed to bring clarity and insight. It is associated with wisdom and truth, and it is often used in meditation and spiritual practices. Zircon is also believed to have protective properties and to enhance one’s ability to communicate and express oneself effectively.
These metaphysical beliefs add another layer of meaning to December’s birthstones, making them not only beautiful but also powerful symbols of personal and spiritual growth.
Care and Cleaning
Proper care and maintenance are essential for preserving the beauty and longevity of gemstones. December’s birthstones require specific attention due to their varying hardness, porosity, and chemical sensitivity.
Turquoise is a relatively soft and porous stone, making it sensitive to water, heat, and chemicals. It should be stored in a cool, dry place and kept away from direct sunlight. Cleaning should be done gently, using a soft cloth and a mild soap solution. Avoid using ultrasonic cleaners or steam cleaners, as these can damage the stone.
Tanzanite is more durable than turquoise, with a hardness of 6.5–7. However, it is still a sensitive gemstone that can be affected by exposure to strong light and heat. It should be cleaned with a soft cloth and a mild soap solution. Avoid using harsh chemicals or abrasive materials, as these can scratch the surface of the stone.
Zircon, especially the blue variety, is relatively hard and durable. It can be cleaned using a soft cloth and a mild soap solution. However, care should be taken to avoid exposing it to high heat, as this can cause changes in color and clarity. Zircon should be stored separately from other gemstones to prevent scratches.
By following these care and cleaning guidelines, you can ensure that your December birthstone remains beautiful and valuable for years to come.
Conclusion
December’s birthstones—Turquoise, Tanzanite, and Zircon—represent a rich and diverse collection of gemstones that reflect the month’s unique character. Their blue and blue-green hues capture the serene beauty of winter, while their geological and cultural histories add depth and meaning to their significance. Whether worn as jewelry, used in rituals, or simply admired for their beauty, these stones are a testament to the enduring appeal of gemstones and their role in human history and culture.
Each of these gemstones has its own set of properties and symbolism, making them not only beautiful but also meaningful. Understanding their gemological characteristics, historical significance, and care requirements allows us to appreciate and preserve them properly. Whether you are a gemstone enthusiast, a jewelry buyer, or simply someone born in December, these stones offer a connection to the past and a celebration of the present.