December is one of the most colorful months in the world of birthstones, offering a rich selection of gemstones that span the spectrum from deep blues to vibrant greens. While the modern jewelry industry recognizes five primary birthstones for December—blue zircon, blue topaz, tanzanite, lapis lazuli, and turquoise—each of these gems carries a distinct history, symbolism, and set of properties that make them unique. This article explores the gemological characteristics, historical significance, cultural symbolism, and care requirements of these December birthstones, drawing from authoritative sources in gemology and cultural history.
Historical Roots and Cultural Significance
The concept of birthstones dates back to ancient times, with early references found in religious and mythological texts. The earliest known association between gemstones and months appears in the Bible, where the High Priest’s breastplate is said to have contained 12 stones representing the 12 tribes of Israel. However, the modern system of assigning gemstones to months was formalized in the early 20th century, with the 1912 Kansas list marking a pivotal moment in standardizing birthstone associations in English-speaking countries.
December's selection of birthstones reflects a blend of traditional and modern influences. While lapis lazuli and turquoise have been traditionally linked to the month for centuries, blue zircon, blue topaz, and tanzanite were added more recently to expand the range of options available to consumers. The inclusion of multiple birthstones for December allows for greater personalization and reflects the diverse cultural and geological contexts in which these gems have been cherished.
Lapis lazuli, one of the older traditional birthstones for December, has been prized since antiquity. It was used by ancient Egyptians, Mesopotamians, and other early civilizations for both decorative and symbolic purposes. In ancient Egypt, lapis lazuli was associated with divinity and was often ground into a pigment for use in cosmetics and religious art. Its deep blue color, flecked with golden pyrite, was believed to represent the heavens and was linked to wisdom, truth, and spiritual insight.
Turquoise, another traditional December birthstone, has been revered for millennia across various cultures. In ancient Mesoamerica, the Aztecs considered turquoise a sacred stone associated with the gods, particularly Quetzalcoatl. In the Middle East, it was used in jewelry and amulets, often believed to offer protection and good fortune. In the United States, Native American tribes have long used turquoise in their jewelry-making traditions, associating it with healing, vitality, and connection to nature.
Blue zircon, blue topaz, and tanzanite are more modern additions to the December birthstone list. Zircon, in particular, has a long geological history, with some varieties being among the oldest minerals on Earth. Its fiery brilliance and ability to display a range of colors made it a natural choice for inclusion in the December lineup. Blue topaz, known for its calming blue hues, was added in the mid-20th century as a more affordable and accessible option for jewelry. Tanzanite, a relatively recent discovery from Tanzania, was officially recognized as a December birthstone in 2002 due to its unique violet-blue color and limited geographic source.
The modern birthstone list for December was updated in 1952 and 2002, reflecting changes in consumer preferences and the availability of new gemstone varieties. These updates were driven by industry organizations such as the American Gem Trade Association (AGTA) and the Jewelers of America (JA), which sought to standardize and promote the use of birthstones in jewelry.
Geological Formation and Sources
Each December birthstone has a distinct geological origin and formation process that contributes to its unique properties and appearance.
Lapis Lazuli is a metamorphic rock composed primarily of lazurite, a sodium calcium aluminum silicate with sulfur. It is typically found in areas where tectonic activity has brought deep-seated minerals to the surface. The most famous source of high-quality lapis lazuli is the Kafiristan region of Afghanistan, where it has been mined for thousands of years. Other notable sources include Russia, Chile, and the United States. The presence of gold-like flecks of pyrite gives lapis lazuli its characteristic "starry" appearance.
Turquoise is a hydrated phosphate of aluminum and copper, formed in the oxidation zones of copper deposits. It is typically found in arid regions where water percolates through copper-rich rock, creating veins of the gemstone. The most well-known source of turquoise is the United States, particularly in the Southwest, where Native American artisans have long used it in their jewelry. Other major sources include China, Iran, and Egypt.
Zircon is a mineral that occurs in a wide range of colors, from colorless to yellow, red, and blue. The blue color in zircon is typically the result of heat treatment, which alters the crystal structure and enhances the stone's brilliance. Zircon is found in various parts of the world, including Sri Lanka, Myanmar, and Australia. Its high refractive index and dispersion make it one of the most brilliant gemstones in the world.
Topaz is a silicate mineral that forms in igneous rocks. The blue color of topaz is due to irradiation, which alters the structure of the crystal and creates a blue hue. Blue topaz is typically found in Brazil, the United States, and Nigeria. It is one of the most popular gemstones for December due to its affordability and versatility in jewelry.
Tanzanite is a relatively rare gemstone that is only found in a small area near Mount Kilimanjaro in Tanzania. It is a form of the mineral zoisite and is known for its striking blue to violet color. Tanzanite was first discovered in 1967 and was named after its country of origin. Its limited availability and vibrant color have made it a highly sought-after gemstone in the jewelry industry.
Gemological Properties
Understanding the gemological properties of December birthstones is essential for both collectors and jewelry wearers. These properties include hardness, refractive index, color, clarity, and durability, all of which affect how the stones are used in jewelry and how they should be cared for.
| Gemstone | Color | Hardness (Mohs) | Refractive Index | Chemical Composition | Origin |
|---|---|---|---|---|---|
| Lapis Lazuli | Deep blue with gold flecks | 5–6 | 1.5–1.7 | Sodium calcium aluminum silicate with sulfur | Afghanistan, Chile, Russia |
| Turquoise | Blue-green | 5–6 | 1.61–1.65 | Hydrated phosphate of aluminum and copper | United States, China, Iran |
| Zircon | Blue, yellow, red | 6–7.5 | 1.92–2.01 | Zirconium silicate (ZrSiO₄) | Sri Lanka, Myanmar, Australia |
| Topaz | Blue | 8 | 1.62–1.64 | Aluminum silicate (Al₂SiO₆) | Brazil, United States, Nigeria |
| Tanzanite | Blue to violet | 6–7 | 1.69–1.70 | Calcium aluminum silicate (Ca₂Al₃(SiO₄)₃(OH)) | Tanzania |
Lapis Lazuli is a metamorphic rock rather than a single mineral, and its hardness ranges from 5 to 6 on the Mohs scale. It is relatively soft compared to other gemstones and is prone to scratching and chipping. Its refractive index is low, and it is typically opaque, with only the finest specimens showing translucency. Due to its softness, lapis lazuli is best suited for pendants, earrings, and other jewelry that is less likely to be subjected to impact.
Turquoise is a soft gemstone with a hardness of 5 to 6 on the Mohs scale. It is also prone to scratching and can be affected by heat and chemicals. Its refractive index is relatively low, and it is typically opaque or slightly translucent. The presence of water in its structure makes turquoise sensitive to dehydration, which can cause it to crack or lose color. Proper care is essential to maintain its appearance.
Zircon is one of the hardest December birthstones, with a hardness of 6 to 7.5 on the Mohs scale. It is known for its high refractive index and dispersion, which give it a brilliant, fiery appearance. Zircon is typically found in a range of colors, with blue being the most popular for December. The blue color is the result of heat treatment, and some zircons may revert to their original color if exposed to prolonged light or heat.
Topaz is one of the hardest December birthstones, with a hardness of 8 on the Mohs scale. It is known for its clarity and brilliance, and it is often used in a variety of jewelry styles, including rings, earrings, and pendants. Blue topaz is the most common variety used for December and is typically created through irradiation. It is stable under normal light conditions and is resistant to most chemicals.
Tanzanite is a relatively soft gemstone with a hardness of 6 to 7 on the Mohs scale. It is known for its vibrant blue to violet color, which is the result of trace amounts of vanadium in its structure. Tanzanite is sensitive to heat and light, and it can lose its color if exposed to high temperatures or prolonged sunlight. It is also sensitive to chemicals and should be cleaned carefully to avoid damage.
Symbolism and Metaphysical Beliefs
The December birthstones have long been associated with a range of symbolic and metaphysical beliefs, many of which have roots in ancient traditions and cultural practices.
Lapis Lazuli is often associated with wisdom, truth, and spiritual insight. In ancient Egypt, it was believed to connect the wearer with the divine and was used in religious ceremonies and royal regalia. It is also associated with inner peace and emotional balance, making it a popular stone for meditation and self-reflection.
Turquoise has been revered for its protective and healing properties. In many cultures, it is considered a talisman for good fortune, protection, and positive energy. It is believed to promote calmness, creativity, and emotional stability. In Native American traditions, turquoise is considered a sacred stone that connects the earth and sky and is used in rituals for healing and protection.
Zircon is known for its brilliance and is often associated with transformation, clarity, and spiritual awakening. It is believed to enhance the wearer's ability to see through illusions and to gain a deeper understanding of the self. Zircon is also associated with the stars and is believed to bring guidance and inspiration.
Topaz is associated with strength, clarity, and emotional balance. It is believed to help the wearer overcome fears and to promote a sense of calm and confidence. Blue topaz is particularly associated with serenity and is often used to promote a sense of peace and tranquility.
Tanzanite is a relatively new gemstone in terms of its recognition as a birthstone, but it has quickly gained popularity for its unique color and metaphysical properties. It is associated with transformation, intuition, and spiritual growth. It is believed to help the wearer access higher levels of consciousness and to enhance their ability to communicate with the spiritual realm.
Care and Cleaning
Proper care and cleaning are essential for maintaining the beauty and longevity of December birthstones. Each gemstone has specific requirements based on its hardness, sensitivity to light and chemicals, and susceptibility to scratches and fractures.
Lapis Lazuli should be handled with care to avoid scratches and chips. It is best to avoid exposure to harsh chemicals, heat, and abrasive cleaners. To clean lapis lazuli, use a soft cloth and mild soap with warm water. Avoid using ultrasonic or steam cleaners, as these can damage the stone.
Turquoise is sensitive to heat, chemicals, and dehydration. It should be stored in a cool, dry place and kept away from direct sunlight. To clean turquoise, use a soft cloth and mild soap with warm water. Avoid using harsh chemicals, abrasive materials, or ultrasonic cleaners, as these can damage the stone.
Zircon is relatively durable but should be handled with care to avoid scratches. It is stable under normal light conditions but should be kept away from prolonged exposure to bright light, as this can cause some heat-treated stones to revert to their original color. To clean zircon, use a soft brush and mild soap with warm water. Avoid using ultrasonic or steam cleaners, as these can damage the stone.
Topaz is one of the hardest December birthstones and is generally easy to care for. It is resistant to most chemicals and is stable under normal light conditions. To clean topaz, use a soft brush and mild soap with warm water. Ultrasonic and steam cleaners can be used safely, but it is best to follow the manufacturer's recommendations.
Tanzanite is sensitive to heat and light and should be stored in a cool, dark place to prevent fading. It is also sensitive to chemicals and should be cleaned with a soft cloth and mild soap with warm water. Avoid using ultrasonic or steam cleaners, as these can damage the stone.
Conclusion
December is a month rich in gemstone diversity, offering a selection of birthstones that reflect the vibrant colors and deep symbolism of the season. From the ancient allure of lapis lazuli and turquoise to the modern brilliance of blue zircon, blue topaz, and tanzanite, each of these gemstones carries its own unique history and significance. Whether chosen for their beauty, their cultural meaning, or their metaphysical properties, December birthstones are more than just decorative stones—they are a connection to the past and a celebration of individuality.
For those born in December, the choice of a birthstone can be a deeply personal one, reflecting not only the gem's appearance but also its meaning and history. By understanding the properties, symbolism, and care requirements of these gemstones, wearers can ensure that their December birthstones remain beautiful and meaningful for years to come.