The transition from the end of December into the early days of January marks a unique astrological period, aligning with the earth sign of Capricorn. Governed by the planet Saturn, Capricorns are characterized by their ambition, discipline, and practical nature. For those born under this sign, particularly in the month of December, the traditional birthstones are a trio of gemstones that reflect the cool, serene tones of winter: turquoise, tanzanite, and zircon. These stones are more than mere adornments; they are historically significant, geologically fascinating, and culturally rich, offering symbolic support to the steadfast Capricorn personality. This article delves into the history, formation, properties, and metaphysical significance of these three December birthstones, providing a comprehensive guide for gemstone enthusiasts, jewelry buyers, and students of gemology.
History and Lore
The tradition of associating specific gemstones with months of the year has deep historical roots, with early references appearing in biblical texts and medieval European jewelry practices. For Capricorns born in December, the primary birthstones—turquoise, tanzanite, and zircon—each possess a distinct narrative that contributes to their enduring appeal.
Turquoise is the original December birthstone, an opaque, blue-green gem that has adorned royalty and common folk alike throughout history. Its use is particularly prominent in Native American cultures, where it was believed to possess mystical abilities. Among Apache shamans, owning turquoise was considered essential to their legitimacy. The stone’s color, symbolizing the sea and sky, offers a contrast to the grounded, earth-sign energy of Capricorn, potentially providing these individuals with greater freedom to explore their talents beyond their daily routines.
Tanzanite is a modern addition to the birthstone calendar. It was first discovered in 1967 and was officially recognized as a December birthstone by the American Gem Trade Association in 2002. Its rarity, being sourced exclusively from Tanzania, adds to its allure. Metaphysically, tanzanite symbolizes traits highly valued by Capricorns: wisdom, honor, and honesty. It is also said to help align the heart’s desires with the mind’s practicality, aiding in fulfilling decision-making.
Zircon, another December birthstone, has a long and varied history, having been used in jewelry for thousands of years. It is sometimes confused with cubic zirconia, a synthetic material, but natural zircon is a gemstone in its own right. Varieties such as cushion zircon and hyacinth zircon are renowned for their brilliance and refractive qualities. Zircon is associated with prosperity, self-worth, and clarity of purpose. It is believed to enhance self-confidence and aid in making clear, decisive choices, qualities that resonate deeply with the Capricorn personality.
Geological Formation and Sources
Understanding the geological processes that create these gemstones provides insight into their rarity, beauty, and value. Each of the December birthstones has a distinct formation process and is found in specific regions around the world.
Turquoise Turquoise is an amorphous hydrous phosphate of aluminum and copper, with the chemical formula CuAl₆(PO₄)₄(OH)₈·4H₂O. It forms in the oxidation zones of copper deposits, where copper-bearing minerals are exposed to rainwater and other surface waters. Major sources of turquoise include Iran, the United States (particularly in states like Arizona and Nevada), Tibet, and India.
Tanzanite Tanzanite is a modern discovery, first found in 1967. It is one of the rarest gems, sourced exclusively from a single location in Tanzania. Its formation is linked to specific geological conditions in the Merelani Hills, making it a truly localized gemstone with limited availability.
Zircon Zircon is one of the world’s oldest known gemstones, with an Australian zircon dated at 4.4 billion years old. It forms in igneous and metamorphic rocks and is found in various locations worldwide. The most popular variety is blue zircon, which is often heat-treated to enhance its color. Zircon’s association with Capricorn’s ruling planet, Saturn, in Vedic astrology adds another layer of its significance.
Gemological Properties
The physical and chemical properties of these gemstones determine their durability, appearance, and suitability for jewelry. The following table summarizes key gemological data for turquoise, tanzanite, and zircon, based on information from the provided sources.
| Gemstone | Mineral Group | Chemical Formula | Mohs Hardness | Color Range | Notable Properties |
|---|---|---|---|---|---|
| Turquoise | Phosphate | CuAl₆(PO₄)₄(OH)₈·4H₂O | 5 – 6 | Sky blue, greenish-blue | Opaque, often with black inclusions; amorphous structure. |
| Tanzanite | Zoisite | Ca₂Al₃(SiO₄)₃(OH) | 6.5 – 7 | Blue, violet, violet-blue | Pleochroic (shows different colors from different angles); trichroic in some cases. |
| Zircon | Zirconium silicate | ZrSiO₄ | 7.5 | Blue (most popular), also brown, green, yellow, red | High refractive index and dispersion (fire); often heat-treated for color. |
Turquoise has a Mohs hardness of 5 to 6, making it relatively soft compared to other gemstones. It is typically opaque and can exhibit a range of blue to green hues, often with a matrix of darker minerals, such as iron or limonite, creating characteristic black or brown webbing. Its amorphous nature means it lacks a crystalline structure, which contributes to its unique, waxy luster.
Tanzanite belongs to the zoisite mineral group and has a Mohs hardness of 6.5 to 7, making it more durable than turquoise but still requiring care in jewelry settings. It is prized for its intense blue to violet colors, which result from heat treatment of the naturally brownish zoisite crystals. Tanzanite is strongly pleochroic, meaning it exhibits different colors—typically blue, violet, and burgundy—when viewed from different crystal directions. This property is a key identifier for gemologists.
Zircon is one of the hardest gemstones in this group, with a Mohs hardness of 7.5, making it excellent for all types of jewelry. It is not to be confused with cubic zirconia, a synthetic simulant. Natural zircon has a high refractive index and high dispersion, giving it exceptional brilliance and fire, often surpassing that of diamond. The most sought-after color is a vivid blue, which is typically achieved through heat treatment of brown zircon crystals. Zircon is also notable for being the oldest known terrestrial material, with some crystals dating back billions of years.
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, these gemstones are imbued with symbolic meanings and metaphysical properties that align with the characteristics of the Capricorn sign.
Turquoise is traditionally associated with friendship, protection, and good fortune. In many cultures, it is considered a sacred stone. For Capricorns, whose earth-sign energy is grounded and practical, turquoise offers a connection to the elemental forces of water and sky, encouraging exploration of creativity and intuition beyond their usual disciplined routines. It is believed to provide emotional balance and protection during times of stress.
Tanzanite symbolizes wisdom, honor, and honesty—traits that resonate with the Capricorn’s disciplined and responsible nature. Metaphysically, it is said to facilitate a connection between the heart and mind, helping Capricorns make decisions that are both emotionally fulfilling and practically sound. Its rarity and unique color are also thought to inspire transformation and spiritual awakening, supporting personal and professional growth.
Zircon is linked to prosperity, self-worth, and clarity of purpose. It is believed to enhance self-confidence and aid in making clear, decisive choices, which are essential for the ambitious and goal-oriented Capricorn. The association of blue zircon with Saturn, Capricorn’s ruling planet, in Vedic astrology further strengthens its connection to this sign. Zircon’s brilliance is thought to mirror the clarity of thought and purpose that Capricorns strive to achieve.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of these gemstones, given their distinct physical properties.
Turquoise, with its relatively low hardness of 5–6 and porous nature, is susceptible to scratches, chemicals, and moisture. It should be cleaned with a soft, dry cloth. Avoid ultrasonic cleaners, steam cleaners, and exposure to lotions, perfumes, or household chemicals, which can damage the stone’s surface and cause discoloration. Store turquoise jewelry separately to prevent scratches from harder materials.
Tanzanite has a hardness of 6.5–7, making it moderately durable. However, it can be prone to chipping if struck against a hard surface due to its cleavage. Clean tanzanite with warm, soapy water and a soft brush. Avoid sudden temperature changes and ultrasonic cleaners, which can cause fractures. It is best to remove tanzanite jewelry during strenuous activities.
Zircon, with a hardness of 7.5, is one of the more durable gemstones in this group. It is resistant to scratching but can be brittle and may chip if impacted. Clean zircon with warm, soapy water and a soft brush. While it is generally safe for ultrasonic cleaners, it is advisable to check with a professional jeweler first, especially if the stone has inclusions or is set in a delicate setting. Avoid exposure to extreme heat, as this can alter its color.
Conclusion
The December birthstones for Capricorn—turquoise, tanzanite, and zircon—offer a compelling blend of historical significance, geological wonder, and metaphysical symbolism. Turquoise, the original December stone, provides protection and a connection to nature. Tanzanite, the modern rarity, brings wisdom and clarity, aiding in the alignment of heart and mind. Zircon, the ancient gem, enhances self-worth and decisive action, mirroring the ambitious nature of Capricorn. Together, they form a triad of gemstones that not only reflect the cool tones of winter but also support the disciplined and goal-oriented journey of those born under the sign of the goat. For gemstone enthusiasts and jewelry buyers, understanding these stones’ properties and lore enriches their appreciation, whether for personal wear or as a thoughtful gift for a December-born Capricorn.