December, the final month of the calendar year, is marked by a unique gemstone tradition that dates back centuries. Those born during this month are symbolically linked to a selection of gemstones—each with distinct characteristics, historical significance, and cultural meanings. The December birthstone tradition is particularly notable for its variety: December has multiple birthstones, including zircon, topaz, tanzanite, lapis lazuli, and turquoise. This article provides a comprehensive exploration of these gems, focusing on their gemological properties, historical and cultural uses, and symbolic meanings. The emphasis is on their shared role as December birthstones, with special attention to zircon, tanzanite, and turquoise—three of the most prominent and well-documented gems for this month.
History and Lore
The tradition of assigning gemstones to birth months has ancient roots, with some of the earliest references dating back to biblical and classical times. The December birthstone tradition, in particular, reflects the rich tapestry of global cultural exchanges over centuries. The sources highlight that December has historically been associated with multiple gemstones, with turquoise and zircon being among the earliest recognized as December birthstones.
Turquoise, for example, was a favored gemstone in ancient Persia, the Sinai Peninsula, and Tibet. Its name derives from the trade routes through Constantinople (modern-day Istanbul), where the gem was introduced to Europe. The sources note that turquoise was highly valued for its protective properties and was often used as an amulet. In Tibet, it was even used as a form of currency, underscoring its cultural and economic significance. The ancient Incas and Mayas also revered turquoise, offering it as a gift to their gods. Native American tribes in the southwestern United States associated turquoise with youth and strength, and when paired with gold, it was believed to symbolize vitality and longevity.
Zircon, another key December birthstone, has a similarly storied past. The name "zircon" is of Arabic origin, meaning "jewel," and in Sanskrit, it is referred to as "rahuratna," or the tone of the lunar nodes. Zircon was historically used in medieval Europe by physicians, who believed it aided in diagnosis. The sources also note that zircon was thought to ward off evil spirits and was used as an amulet during the Black Death in Europe. In India, zircon was believed to have greater potency when set in gold, and it was considered a powerful talisman for protection.
Tanzanite, the newest of the December birthstones, was first discovered in 1967 in the Merelani Hills of northern Tanzania. Its name is derived from its country of origin, and it is unique in that it is only found in this region. Tanzanite’s deep blue and violet hues quickly made it a favorite in the gemstone trade. Its modern introduction to the December birthstone list in the 1960s marked a significant shift in the tradition, adding a contemporary gem to a list that had previously relied on older, more established stones.
The tradition of having multiple December birthstones serves both practical and symbolic purposes. It allows individuals to choose a gemstone that aligns with their personal preferences, budget, and cultural background. The sources also emphasize that these gemstones reflect the diversity of December itself, spanning from ancient traditions to modern discoveries.
Geological Formation and Sources
The December birthstones come from a variety of geological formations and geographic locations. Each gemstone has its own unique formation process and source regions, which contribute to its rarity and beauty.
Turquoise is a hydrated phosphate of aluminum and copper, with the chemical formula CuAl₆(PO₄)₄(OH)₈·4H₂O. It forms in arid regions where copper deposits are exposed to the weathering effects of water. The finest turquoise is typically found in Persian, Egyptian, and American sources. Persian turquoise, known for its vivid blue color and minimal matrix, is highly prized in the gemstone market. American turquoise, particularly from the Southwest, is valued for its vibrant blue-green hues and distinctive matrix patterns.
Zircon is a zirconium silicate (ZrSiO₄) that occurs in a wide range of colors, including colorless, yellow, red, and blue. The most valuable zircons for December are the blue and colorless varieties, with blue zircon often being heat-treated to enhance its color. Zircon is found in metamorphic and igneous rocks and is often recovered as a heavy mineral in alluvial deposits. Major sources include Australia, South Africa, Sri Lanka, and India, which collectively produce about 70% of the world’s zircon gemstones.
Tanzanite is a variety of the mineral zoisite, with the chemical formula Ca₂Al₃(SiO₄)(OH)₃·(OH). It is unique for its pleochroism, which means it displays different colors when viewed from different angles—ranging from blue to violet. Tanzanite is only found in the Merelani Hills of northern Tanzania, near Mount Kilimanjaro. The gemstone’s limited source makes it a highly valuable and collectible stone. Its rarity and vibrant color have made it a popular choice for jewelry, particularly in modern designs.
Lapis lazuli, another December birthstone, is a metamorphic rock composed primarily of lazurite, with pyrite and calcite as common inclusions. The deep blue color of lapis lazuli is due to the presence of lazurite, and the golden flecks of pyrite add to its visual appeal. Lapis lazuli has been mined for thousands of years, with the most famous source being the mines in Afghanistan. Ancient Egyptians and Mesopotamians used lapis lazuli for jewelry and ceremonial objects, and it was often associated with royalty and divinity.
Topaz, the final gemstone listed among December’s birthstones, is a silicate mineral with the chemical formula Al₂SiO₄(F,OH)₂. Blue topaz is the most popular variety for December and is typically treated with irradiation and heat to achieve its blue color. Topaz is found in igneous and metamorphic rocks and is mined in several countries, including Brazil, Mexico, and the United States.
The availability of these gemstones in various colors and from different sources contributes to the diversity of December’s birthstone offerings. Whether one prefers the ancient allure of turquoise, the brilliance of zircon, or the modern elegance of tanzanite, there is a December birthstone to suit every taste.
Gemological Properties
The gemological properties of December’s birthstones vary significantly, reflecting their different mineral compositions and origins. These properties—such as hardness, refractive index, and color—are essential in determining how these gemstones are used in jewelry and how they should be cared for.
| Gemstone | Chemical Formula | Color Varieties | Hardness (Mohs Scale) | Refractive Index | Specific Gravity | Transparency |
|---|---|---|---|---|---|---|
| Turquoise | CuAl₆(PO₄)₄(OH)₈·4H₂O | Blue, green, white, brown matrix | 5–6 | 1.61–1.65 | 2.6–2.8 | Opaque |
| Zircon | ZrSiO₄ | Colorless, yellow, red, blue | 6–7.5 | 1.92–2.01 | 3.9–4.7 | Transparent |
| Tanzanite | Ca₂Al₃(SiO₄)(OH)₃·(OH) | Blue, violet, purple | 6–7 | 1.69–1.70 | 3.3–3.4 | Transparent |
| Lapis Lazuli | Lazurite + Pyrite + Calcite | Deep blue with gold pyrite flecks | 5–6 | 1.5–1.7 | 2.4–2.9 | Opaque |
| Topaz | Al₂SiO₄(F,OH)₂ | Blue, yellow, pink, brown, colorless | 8 | 1.61–1.63 | 3.4–3.5 | Transparent |
Turquoise
Turquoise has a hardness of 5 to 6 on the Mohs scale, making it relatively soft and prone to scratches. Its refractive index ranges from 1.61 to 1.65, and it is generally opaque, with color variations due to the presence of different minerals in the matrix. Because of its softness and porosity, turquoise requires careful handling and is not recommended for everyday wear without proper protection.
Zircon
Zircon is a harder gemstone, with a hardness of 6 to 7.5 on the Mohs scale. It is known for its high refractive index (1.92–2.01) and strong dispersion, which gives it a brilliant fire when cut properly. Zircon is available in a range of colors, including colorless (jargoon), yellow, red, and blue. Blue zircon is the most popular for December and is often heat-treated to enhance its color. Its high refractive index makes it appear similar to diamond when colorless, though it is much softer.
Tanzanite
Tanzanite has a hardness of 6 to 7 and a refractive index of 1.69–1.70. It is pleochroic, meaning it displays different colors when viewed from different angles. Tanzanite is known for its deep blue and violet hues, which make it a popular choice for modern jewelry. Its specific gravity is 3.3–3.4, and it is relatively dense compared to other gemstones of similar hardness.
Lapis Lazuli
Lapis lazuli is a metamorphic rock composed of lazurite, pyrite, and calcite. It has a hardness of 5 to 6 and a refractive index ranging from 1.5 to 1.7. The deep blue color of lapis lazuli is due to the presence of lazurite, and the golden flecks of pyrite add to its visual appeal. It is opaque and is often used for cabochons or carved pieces rather than faceted gemstones.
Topaz
Topaz is one of the harder December birthstones, with a hardness of 8 on the Mohs scale. It has a refractive index of 1.61–1.63 and a specific gravity of 3.4–3.5. Blue topaz is the most popular variety for December and is typically irradiated and heat-treated to achieve its blue color. Topaz is durable and suitable for a wide range of jewelry applications, including rings, pendants, and bracelets.
Symbolism and Metaphysical Beliefs
The December birthstones carry a rich array of symbolic and metaphysical beliefs, reflecting their diverse cultural and historical backgrounds.
Turquoise has long been associated with protection, good fortune, and communication. In ancient Tibet, it was believed to bring health, success, and prosperity. Native American tribes in the Southwest used turquoise as a symbol of youth and strength, and it was often combined with gold to represent vitality and longevity. In medieval Europe, turquoise was considered a protective amulet, and it was believed to warn the wearer of illness or danger by changing color.
Zircon is believed to have protective and healing properties. In medieval times, physicians wore zircon on their left fingers as a tool for diagnosis. It was also used as an amulet against the Black Death in Europe. In India, zircon was believed to be more powerful when set in gold, and it was considered a talisman for protection against evil spirits.
Tanzanite is associated with intuition, vitality, and spiritual awakening. It is believed to enhance one’s ability to make intuitive decisions and to bring a sense of calm and balance. Because it is only found in Tanzania, it is also seen as a symbol of uniqueness and individuality. Tanzanite is often used in meditation and is believed to help connect the wearer to their higher self.
Lapis lazuli has long been associated with wisdom, truth, and spiritual insight. In ancient Egypt, it was used in jewelry and ceremonial objects and was believed to be a stone of the gods. The golden flecks of pyrite in lapis lazuli were thought to represent the stars, and it was often used in royal regalia. In medieval Europe, lapis lazuli was believed to promote mental clarity and was used by artists and scholars.
Topaz is associated with strength, vitality, and good fortune. In ancient times, it was believed to have the power to protect against poison and to bring courage to the wearer. In medieval Europe, it was considered a gemstone of the sun and was believed to promote happiness and joy. Blue topaz, in particular, is associated with calm and serenity, making it a popular choice for those seeking emotional balance.
The diverse symbolic and metaphysical beliefs of December’s birthstones reflect their long and storied histories. Whether used for protection, healing, or spiritual insight, these gemstones continue to be cherished for their beauty and meaning.
Care and Cleaning
Proper care and cleaning are essential to maintaining the beauty and longevity of December’s birthstones. Each gemstone has its own unique properties that determine how it should be handled and cleaned.
Turquoise is relatively soft and porous, making it susceptible to damage from harsh chemicals and excessive moisture. It should be cleaned gently with a soft cloth and mild soap and water. It is best to avoid exposure to acids, ammonia, and other harsh cleaning agents. Turquoise should also be stored separately from harder gemstones to prevent scratches. Because of its softness, turquoise is not recommended for everyday wear unless it is properly protected with a setting or coating.
Zircon is harder than turquoise but still requires careful handling. It should be cleaned with warm, soapy water and a soft cloth or brush. Avoid using ultrasonic cleaners, as the high-frequency vibrations can damage the gemstone’s structure. Zircon should also be stored separately from other gemstones to prevent scratches. Because of its high refractive index, zircon should be handled carefully to avoid chipping or breaking.
Tanzanite is relatively durable but can be sensitive to heat and light. Prolonged exposure to direct sunlight or high heat can cause it to fade or lose its color. It should be cleaned with warm, soapy water and a soft cloth or brush. Avoid using ultrasonic or steam cleaners, as these can damage the gemstone. Tanzanite should also be stored in a cool, dark place to maintain its vibrant color.
Lapis lazuli is a relatively soft and porous stone that requires gentle care. It should be cleaned with warm, soapy water and a soft cloth. Avoid using harsh chemicals, as these can damage the stone or remove its polish. Lapis lazuli should also be stored separately from harder gemstones to prevent scratches. Because it is opaque, it is not recommended for faceted designs but is well-suited for cabochons or carved pieces.
Topaz is one of the harder December birthstones and is relatively easy to care for. It can be cleaned with warm, soapy water and a soft cloth or brush. It is also suitable for ultrasonic and steam cleaners, though care should be taken to avoid using these if the topaz is set in a delicate or fragile setting. Topaz should be stored separately from other gemstones to prevent scratches.
Proper care and handling are essential to preserving the beauty and value of December’s birthstones. Whether you own a piece of turquoise, zircon, tanzanite, lapis lazuli, or topaz, following these care instructions will help ensure that your gemstone remains vibrant and beautiful for years to come.
Conclusion
December’s birthstones offer a rich and diverse selection of gemstones, each with its own unique history, symbolism, and gemological properties. From the ancient allure of turquoise and zircon to the modern elegance of tanzanite, these gems reflect the month’s historical and cultural significance. The tradition of assigning multiple birthstones to December allows individuals to choose a gemstone that best suits their personal style, preferences, and beliefs.
The December birthstones have been cherished for centuries, with their use dating back to ancient civilizations. Turquoise, zircon, and lapis lazuli were among the earliest recognized as December birthstones, while tanzanite and topaz were later added to the list. Each gemstone carries its own set of symbolic and metaphysical beliefs, from protection and good fortune to intuition and spiritual insight. These beliefs, rooted in history and tradition, continue to influence the way these gemstones are used in jewelry and personal adornment.
From a gemological perspective, December’s birthstones vary in hardness, refractive index, and other properties, making them suitable for a wide range of jewelry applications. Whether used in rings, pendants, or other designs, these gemstones offer a beautiful and meaningful way to express individuality and style. Proper care and handling are essential to maintaining their beauty and value, and following the recommended care instructions will help ensure that these gems remain vibrant and beautiful for generations.
The December birthstone tradition is a testament to the enduring appeal of gemstones and their ability to connect us to history, culture, and personal meaning. Whether you are a gemstone enthusiast, a jewelry buyer, or a student of gemology, the December birthstones offer a fascinating and rewarding subject of study and appreciation.