December is one of the few months that boasts multiple birthstones, each with its own unique beauty, history, and symbolism. From the deep blue allure of lapis lazuli to the vibrant hues of turquoise and the modern elegance of tanzanite and blue zircon, December birthstones offer a rich tapestry of color, meaning, and cultural significance. This article delves into the gemological properties, historical origins, and symbolic meanings of these stones, offering a comprehensive guide for gemstone enthusiasts, jewelry buyers, and those curious about the traditions behind these December gems.
Introduction
December, often associated with the end of the year and the beginning of winter, is also marked by a fascinating collection of birthstones. Unlike months that feature a single gemstone, December has five traditional birthstones: blue zircon, blue topaz, tanzanite, lapis lazuli, and turquoise. These stones vary in color, composition, and cultural significance, making December a particularly rich month in the world of gemstones. This article explores the origins, properties, and symbolism of these stones, drawing from historical records, modern practices, and contemporary interpretations.
History and Lore
The concept of birthstones dates back to ancient times, with roots in biblical and medieval traditions. The earliest recorded list of birthstones is found in the Old Testament, in the Breastplate of Aaron, where 12 gemstones were described as representing the 12 tribes of Israel. However, the association of these stones with specific months came much later. By the 19th and 20th centuries, various organizations and jewelers began standardizing the modern birthstone list, and December's selection evolved significantly over time.
The Evolution of December Birthstones
The history of December’s birthstones reflects a gradual shift in both cultural preferences and scientific understanding. According to the earliest lists, ruby was considered the December birthstone, but this designation has since been replaced. By the 1870s, turquoise was introduced as the primary December gem by Tiffany & Co. in their "Gregorian Birthstone Poems" pamphlet. In 1912, the National Association of Jewellers (now Jewellers of America) listed turquoise as the main December birthstone and included lapis lazuli as an alternative.
In 1952, zircon was added to the list by the Jewelry Industry Council of America, and in 2002, tanzanite was officially recognized as a December birthstone. This expansion reflects not only the changing tastes of consumers but also the discovery of new gemstone varieties and the growing appreciation for semi-precious stones.
Cultural and Symbolic Significance
Throughout history, the stones associated with December have been regarded as symbols of protection, wisdom, and transformation. Lapis lazuli, for example, was highly prized in ancient Egypt and Mesopotamia, where it was used in jewelry and religious artifacts. Its deep blue color was believed to represent the heavens, and it was often worn by royalty as a symbol of power and knowledge.
Turquoise, another traditional December birthstone, has a long history in Mesoamerican and Asian cultures. It was used in rituals, amulets, and even as currency. In Native American traditions, turquoise is considered a sacred stone that brings good fortune and spiritual guidance. Its blue-green color is thought to bridge the earth and sky, making it a powerful symbol of harmony and balance.
Tanzanite, a relatively modern addition to the December birthstone list, was first discovered in Tanzania in 1967. Its striking blue to violet color and limited geographic origin make it a unique and sought-after gemstone. As the only gemstone found in a single location on Earth, tanzanite carries a sense of exclusivity and rarity.
Blue zircon, another modern December birthstone, is known for its brilliance and color variety. Found in ancient deposits around the world, zircon has been used in jewelry for thousands of years. Its refractive properties give it a fire similar to diamonds, making it a popular alternative for those seeking a more affordable option.
Geological Formation and Sources
Each December birthstone has a distinct geological origin, formed through different processes and found in specific regions of the world. Understanding these origins provides insight into the rarity and value of each gemstone.
Blue Zircon
Blue zircon is a metamorphic gemstone formed when zircon crystals are subjected to natural radiation, which alters their color. The most well-known source of blue zircon is in Thailand, although it is also found in Australia, Sri Lanka, and Brazil. Zircon is one of the oldest minerals on Earth, with some crystals dating back over 4 billion years. This makes blue zircon not only a beautiful gemstone but also a piece of geological history.
Tanzanite
Tanzanite is a type of zoisite that was first discovered near Mount Kilimanjaro in Tanzania in 1967. It is the only gemstone that can only be found in one location on the planet, making it one of the rarest gemstones in the world. The gemstone is formed under specific geological conditions involving high heat and pressure, which cause the transformation of zoisite into its blue-violet form. Tanzanite is often heat-treated to enhance its color, a process that is widely accepted in the gemstone industry.
Turquoise
Turquoise is an aluminum phosphate mineral that forms in the oxidized zones of copper deposits. It is most commonly found in arid regions with alkaline soil, such as the southwestern United States, Iran, and Tibet. The most highly prized turquoise comes from the Sleeping Beauty Mine in Arizona, which produces a bright blue stone with minimal matrix. Turquoise from Iran is also highly valued for its deep blue color and dark matrix.
Lapis Lazuli
Lapis lazuli is a metamorphic rock composed primarily of lazurite, a type of feldspar. It is formed when sodium-rich fluids interact with limestone under high pressure and temperature. The most famous source of lapis lazuli is Afghanistan, where it has been mined for thousands of years. Other sources include Chile, Russia, and India. High-quality lapis lazuli is characterized by its deep blue color and flecks of gold-colored pyrite, which add to its visual appeal.
Blue Topaz
Blue topaz is a color-treated form of natural topaz, which is typically colorless or pale yellow. The blue color is achieved through irradiation and heat treatment, processes that are widely accepted in the gemstone industry. Natural blue topaz is extremely rare, so the majority of blue topaz on the market is treated. The gemstone is found in various parts of the world, including Brazil, Nigeria, and the United States.
Gemological Properties
Understanding the physical and chemical properties of December birthstones is essential for both gemologists and jewelry buyers. These properties determine the durability, appearance, and value of each gemstone.
Blue Zircon
- Chemical Formula: ZrSiO₄
- Hardness (Mohs Scale): 6.5–7.5
- Refractive Index: 1.92–2.00
- Color: Blue (due to natural radiation)
- Clarity: Often included; inclusions are common
- Cut: Typically faceted
- Luster: Vitreous
- Specific Gravity: 4.6–4.7
Blue zircon is known for its high refractive index, which gives it a brilliant, fire-like appearance. It is relatively durable but can be sensitive to heat and abrasion. Zircon is often confused with diamond due to its brilliance, but its lower hardness and different refractive properties make it distinguishable under a gemological microscope.
Tanzanite
- Chemical Formula: Ca₂Al₃(SiO₄)(OH)₃
- Hardness (Mohs Scale): 6–7
- Refractive Index: 1.694–1.701
- Color: Blue to violet (due to iron impurities)
- Clarity: Often included; inclusions are common
- Cut: Typically faceted
- Luster: Vitreous
- Specific Gravity: 3.1–3.4
Tanzanite is a relatively soft gemstone, which means it requires careful handling and protection from scratches. Its unique color is a result of trace amounts of iron in the crystal structure. Tanzanite is often heat-treated to enhance its color and improve clarity.
Turquoise
- Chemical Formula: Al₂(SO₄)₃(OH)₆(H₂O)
- Hardness (Mohs Scale): 5–6
- Refractive Index: 1.61–1.65
- Color: Blue to green
- Clarity: Often opaque; inclusions are common
- Cut: Often cabochon
- Luster: Waxy
- Specific Gravity: 2.0–2.8
Turquoise is a relatively soft and porous gemstone, which makes it susceptible to damage from acids, oils, and excessive moisture. It is often stabilized with resins or other materials to improve its durability. Turquoise is typically cut into cabochons rather than facets, as it lacks the refractive properties of transparent gemstones.
Lapis Lazuli
- Chemical Formula: (Na,Ca)₈(AlSiO₄)₆(S,S,OH,O)₁₋x
- Hardness (Mohs Scale): 5–6
- Refractive Index: 1.62–1.64
- Color: Deep blue with gold flecks (pyrite)
- Clarity: Often opaque; inclusions are common
- Cut: Often cabochon
- Luster: Waxy to vitreous
- Specific Gravity: 2.4–2.9
Lapis lazuli is a metamorphic rock rather than a pure gemstone, and it is composed of lazurite, calcite, and pyrite. Its deep blue color and gold flecks make it a visually striking gemstone. Like turquoise, it is typically cut into cabochons and used in decorative items and jewelry.
Blue Topaz
- Chemical Formula: Al₂SiO₄(F,OH)₂
- Hardness (Mohs Scale): 8
- Refractive Index: 1.61–1.63
- Color: Blue (due to irradiation)
- Clarity: Often included; inclusions are common
- Cut: Typically faceted
- Luster: Vitreous
- Specific Gravity: 3.5–3.6
Blue topaz is a relatively durable gemstone with a high hardness that makes it suitable for everyday wear. Its blue color is the result of irradiation and heat treatment, which are widely accepted in the gemstone industry. Natural blue topaz is extremely rare, so the majority of blue topaz on the market is treated.
Symbolism and Metaphysical Beliefs
December birthstones have long been associated with symbolic and metaphysical properties. While these beliefs are not based on scientific evidence, they continue to influence the popularity of these stones in jewelry and personal adornment.
Blue Zircon
Blue zircon is believed to promote clarity of thought and emotional stability. It is associated with wisdom, intuition, and spiritual growth. In some traditions, zircon is thought to enhance one's ability to connect with higher consciousness and access hidden knowledge.
Tanzanite
Tanzanite is often regarded as a stone of transformation and emotional healing. It is believed to help individuals release emotional blockages and find inner peace. Tanzanite is also associated with love and compassion, making it a popular choice for romantic jewelry.
Turquoise
Turquoise is one of the most widely recognized and beloved gemstones in December. It is believed to bring protection, good fortune, and spiritual guidance. In many Native American traditions, turquoise is considered a sacred stone that connects the earth and sky. It is also associated with communication, creativity, and emotional balance.
Lapis Lazuli
Lapis lazuli has long been associated with wisdom, truth, and intellectual clarity. In ancient Egypt, it was worn by royalty as a symbol of power and knowledge. It is believed to enhance one's ability to think clearly and make sound decisions. Lapis lazuli is also associated with spiritual awakening and self-awareness.
Blue Topaz
Blue topaz is thought to promote calmness, serenity, and emotional stability. It is often used in meditation and spiritual practices to help individuals find inner peace and balance. Blue topaz is also associated with love and harmony, making it a popular choice for romantic jewelry.
Care and Cleaning
Proper care and cleaning are essential for preserving the beauty and longevity of December birthstone jewelry. The following guidelines should be followed to ensure that these gems remain in optimal condition.
Blue Zircon
- Avoid heat and abrasion: Blue zircon is sensitive to high heat and can lose its color if exposed to excessive heat.
- Cleaning: Use a soft brush with mild soap and warm water. Avoid ultrasonic cleaners, which can damage the gemstone.
- Storage: Store in a soft cloth or padded jewelry box to prevent scratches.
Tanzanite
- Avoid abrasion and heat: Tanzanite is relatively soft and should be handled with care to avoid scratches and heat damage.
- Cleaning: Use a soft brush with mild soap and warm water. Avoid ultrasonic cleaners and steamers, which can damage the gemstone.
- Storage: Store in a soft cloth or padded jewelry box to prevent scratches.
Turquoise
- Avoid acids and moisture: Turquoise is porous and can be damaged by acids, oils, and excessive moisture.
- Cleaning: Use a soft cloth with mild soap and warm water. Avoid ultrasonic cleaners and steamers.
- Storage: Store in a dry, cool place to prevent cracking or discoloration.
Lapis Lazuli
- Avoid acids and moisture: Lapis lazuli is porous and can be damaged by acids and excessive moisture.
- Cleaning: Use a soft cloth with mild soap and warm water. Avoid ultrasonic cleaners and steamers.
- Storage: Store in a dry, cool place to prevent cracking or discoloration.
Blue Topaz
- Durable but sensitive to heat: Blue topaz is relatively durable but can lose its color if exposed to high heat.
- Cleaning: Use a soft brush with mild soap and warm water. Avoid ultrasonic cleaners and steamers.
- Storage: Store in a soft cloth or padded jewelry box to prevent scratches.
Conclusion
December birthstones offer a unique and diverse collection of gemstones, each with its own history, properties, and symbolism. From the deep blue of lapis lazuli to the vibrant hues of turquoise and the modern elegance of tanzanite and blue zircon, these stones reflect the richness of the month and the people born under its influence. Whether used in jewelry, meditation, or personal adornment, December birthstones continue to captivate and inspire those who wear them. Their enduring appeal is a testament to the timeless allure of gemstones and the stories they carry through history.