December, the final month of the year, is symbolically rich with themes of change, renewal, and celebration. It is also the month that boasts the most diverse selection of birthstones in the calendar year. For those born on December 14th, or indeed any day in December, the choice of gemstones is not limited to one but includes a selection of four: turquoise, tanzanite, zircon (especially blue zircon), and blue topaz. Each of these gemstones carries its own distinct history, geological properties, and cultural significance. This article explores the origins, characteristics, and enduring appeal of these four December birthstones, drawing on a range of historical, scientific, and cultural insights from the available sources.
December has four recognized birthstones: turquoise, tanzanite, zircon, and blue topaz. This collection of gemstones reflects the evolution of birthstone lists over time and the growing recognition of new discoveries in the field of gemology. While some of these gemstones have ancient roots, others, such as tanzanite, are relatively recent additions to the birthstone tradition. Each offers a unique combination of beauty, rarity, and symbolic meaning, making December one of the most intriguing months in the birthstone calendar.
This article will delve into the historical significance of each gemstone, its geological properties, cultural symbolism, and practical considerations for jewelry and care. We will also explore how these gemstones have been integrated into modern jewelry design and what makes them appealing for December-born individuals.
History and Lore of the December Birthstones
The concept of birthstones has ancient roots, tracing back to biblical references and early cultural traditions. According to the Book of Exodus, Aaron’s breastplate was adorned with twelve gemstones, each representing one of the twelve tribes of Israel. Over time, these stones were linked to the months of the year and specific zodiac signs.
December’s birthstones have a particularly dynamic history, with their selection evolving significantly over the centuries. The earliest known birthstone for December was ruby, a gemstone of deep red color and high value. However, this changed in the 19th century when turquoise was introduced as the primary December birthstone by Tiffany & Co. in their "Gregorian Birthstone Poems" pamphlet in 1870.
In 1912, the National Association of Jewellers (now the Jewellers of America) updated the list, designating turquoise as the primary December birthstone and lapis lazuli as an alternative. By 1952, zircon was added to the list, and in 2002, tanzanite was introduced as a fourth option. This expansion of December’s birthstone list reflects both the richness of gemological diversity and the desire to offer more affordable and accessible alternatives to the traditional stones.
The inclusion of multiple birthstones for December also allows for greater flexibility in jewelry design and personal preference. While turquoise has been a favorite for centuries, the introduction of tanzanite and zircon has provided new options with distinct colors and properties.
Turquoise, the oldest of the four, has been used for thousands of years in jewelry and decorative arts. It was especially valued in ancient civilizations such as Mesopotamia, Egypt, and China. The name "turquoise" comes from the French pierre turquesque, meaning "Turkish stone," a reference to the trade routes through which it was introduced to Europe from the East.
Zircon, particularly the blue variety, is another ancient gemstone with a long and varied history. It has been used in jewelry and ceremonial objects for centuries and is known for its high refractive index, which gives it a brilliant, fire-like appearance. Zircon is also notable for its role in scientific research, particularly in the development of radiometric dating techniques.
Tanzanite, the youngest of the four December birthstones, was discovered in the 1960s in Tanzania, from which it takes its name. Unlike the other stones, tanzanite was not a known gem before its discovery. It was found accidentally in a garden on Mount Kilimanjaro and was later identified and marketed as a new and rare gemstone. Its striking blue-violet color quickly made it a favorite among jewelers and collectors.
Blue topaz, while not traditionally listed as a December birthstone, is often included as an alternative due to its similar blue color and availability. It is a more affordable option and is frequently used in jewelry designs that incorporate the December color palette.
Each of these gemstones carries with it a unique cultural and historical legacy, making the December birthstone selection one of the most interesting and diverse in the calendar year.
Geological Formation and Sources of the December Birthstones
The geological processes that form the December birthstones are as varied as the stones themselves. Each gemstone is created through specific conditions involving heat, pressure, and chemical composition, and they are found in distinct locations around the world.
Turquoise
Turquoise is formed in arid environments where copper ore deposits are exposed to weathering and oxidation. The process begins when rainwater or melted snow percolates through copper-rich rocks, dissolving copper sulfides and creating an acidic solution. This solution then interacts with aluminum and phosphorus in the surrounding rock, leading to the formation of turquoise in cavities and cracks. The presence of other minerals can influence the color of turquoise, with copper contributing to blue tones and iron to green.
Turquoise is typically found in weathered volcanic rock and sedimentary rock in arid regions. Major sources of turquoise include the southwestern United States, especially Arizona and New Mexico; Iran (where it has been mined for thousands of years); and Egypt, where it was highly valued in ancient times.
Zircon
Zircon is a mineral that forms in a variety of igneous and metamorphic rocks. It is particularly resistant to weathering and is often found in alluvial deposits after the parent rock has eroded. Zircon is composed of zirconium, silicon, and oxygen, and it can occur in a range of colors, including red, orange, yellow, brown, green, and blue. The blue color in zircon is achieved through heat treatment, which alters the crystal structure and removes hydrogen impurities.
Zircon is found in several countries, including Thailand, Cambodia, Vietnam, and Australia. Large, high-quality blue zircons can be rare and expensive, but the availability of smaller stones makes it a popular choice for jewelry. Zircon is also notable for its scientific significance, as some zircon crystals have been dated to over 4.4 billion years old, making them among the oldest known minerals on Earth.
Tanzanite
Tanzanite is a relatively new gemstone in the birthstone tradition, discovered in 1967 in Tanzania. It is found exclusively in the Merelani Hills near Mount Kilimanjaro, where it forms under high-pressure and high-temperature conditions. Tanzanite is a type of zoisite, a silicate mineral that contains vanadium, which gives it its distinctive blue-violet color.
The formation of tanzanite is unique in that the color change is caused by the presence of trace elements and the crystal structure. When exposed to certain light sources, tanzanite can exhibit a range of colors from deep blue to purple. This color change is due to the way light interacts with the vanadium ions in the crystal lattice.
Because tanzanite is found only in Tanzania, it is considered a rare and valuable gemstone. Its limited geographic source and the specific conditions required for its formation contribute to its exclusivity and desirability in the jewelry market.
Blue Topaz
Blue topaz is a color-treated gemstone that is not naturally blue. The blue color is achieved through irradiation or heat treatment, which alters the crystal structure and creates the blue hue. Natural topaz can occur in a range of colors, including yellow, brown, and pink, but the blue variety is particularly popular due to its vibrant color and affordability.
Blue topaz is mined in several countries, including Brazil, Mexico, and Nigeria. It is often found in large, clear crystals, making it suitable for a wide range of jewelry designs. Blue topaz is also known for its durability, with a hardness of 8 on the Mohs scale, making it more resistant to scratches and damage compared to softer stones like turquoise.
Gemological Properties of the December Birthstones
The gemological properties of the December birthstones—turquoise, tanzanite, zircon, and blue topaz—include their hardness, color, refractive index, and other physical characteristics that influence their use in jewelry and their overall appeal.
Turquoise
Turquoise has a hardness of 5 to 6 on the Mohs scale, making it a relatively soft gemstone that is susceptible to scratches and damage. It is also porous and can absorb oils, dyes, and other substances, which can alter its color and appearance. Turquoise is typically opaque to translucent and has a waxy to greasy luster. It is best suited for jewelry that is worn infrequently or with care, and it should be stored away from direct sunlight and harsh chemicals.
The color of turquoise ranges from blue to green, depending on the presence of copper and iron. Blue turquoise is highly valued, while green turquoise is less common. The presence of black matrix (a network of dark lines or spots) is often considered a desirable feature in turquoise, as it can enhance its beauty and uniqueness.
Zircon
Zircon has a hardness of 6.5 to 7.5 on the Mohs scale, making it more durable than turquoise but less hard than topaz. It has a high refractive index, which gives it a brilliant, fire-like appearance similar to diamonds. Zircon is available in a range of colors, but the blue variety is the most commonly used in jewelry.
Blue zircon is typically heat-treated to achieve its color, and it can be found in alluvial deposits in countries such as Thailand, Cambodia, and Vietnam. Zircon is also known for its high dispersion, which creates a rainbow-like effect when light passes through the stone. This property makes it a popular choice for jewelry that requires a bright, sparkling gemstone.
Tanzanite
Tanzanite has a hardness of 6 to 6.5 on the Mohs scale, making it relatively soft and prone to scratches. It is also sensitive to heat and light, and prolonged exposure can cause it to fade or change color. Tanzanite is a trichromatic gemstone, meaning it can display three different colors—blue, purple, and brown—depending on the light source and viewing angle.
Tanzanite has a refractive index of 1.69 to 1.70, which gives it a moderate brilliance. It is best suited for jewelry that is worn with care and stored in a cool, dark place to preserve its color and clarity. Tanzanite is also known for its pleochroism, the ability to show different colors when viewed from different angles.
Blue Topaz
Blue topaz has a hardness of 8 on the Mohs scale, making it one of the hardest December birthstones. It is durable and resistant to scratches and abrasions, making it suitable for everyday wear. Blue topaz has a refractive index of 1.62 to 1.64, which gives it a clear, bright appearance.
Blue topaz is typically colorless in its natural state but is treated to achieve its blue color. The color treatment process can involve irradiation or heat treatment, which alters the crystal structure and creates the blue hue. Blue topaz is also available in other colors, including golden topaz and pink topaz, but the blue variety is the most popular as a December birthstone.
Symbolism and Metaphysical Beliefs of the December Birthstones
The December birthstones—turquoise, tanzanite, zircon, and blue topaz—have been associated with various symbolic and metaphysical meanings throughout history. These beliefs vary across cultures and time periods, but they often reflect the gemstones’ colors, properties, and uses.
Turquoise
Turquoise has long been associated with protection, good fortune, and spiritual guidance. In ancient cultures, it was believed to ward off evil spirits and bring prosperity. The ancient Egyptians used turquoise in amulets and jewelry to protect against illness and misfortune. In the Middle East, it was considered a symbol of life and vitality, and it was often used in religious and ceremonial objects.
In Native American cultures, particularly among the Navajo and Hopi tribes, turquoise is considered a sacred stone. It is believed to represent the sky and the earth and is used in jewelry and rituals to connect with the spiritual world. Turquoise is also associated with healing, and it has been used in traditional medicine to treat ailments such as fevers and digestive issues.
Zircon
Zircon has been associated with wisdom, strength, and protection in various cultures. In ancient Hindu traditions, zircon was believed to have protective and healing properties. It was used in sacred rituals and was thought to enhance spiritual awareness and clarity of thought. In the 1800s, zircon was referred to as a “glowing stone” and was compared to diamonds in terms of brilliance and beauty.
Zircon was also used in medieval Europe as a protective stone. It was believed to offer protection against the plague and other diseases. Some cultures believed that zircon could help with sleep and reduce nightmares, making it a popular stone for use in bedtime rituals.
Tanzanite
Tanzanite, the newest of the December birthstones, has developed its own set of symbolic meanings since its discovery in the 1960s. It is often associated with emotional healing, transformation, and spiritual growth. The blue-violet color of tanzanite is thought to represent intuition and inner wisdom, and it is believed to help individuals connect with their higher selves.
Tanzanite is also associated with the throat and third eye chakras in spiritual traditions. It is believed to enhance communication, both verbal and non-verbal, and to help individuals express their thoughts and emotions more clearly. Tanzanite is also considered a stone of love and compassion, and it is often used in jewelry and meditation practices to promote emotional balance and harmony.
Blue Topaz
Blue topaz is associated with calmness, clarity, and emotional stability. It is believed to help reduce stress and anxiety and to promote a sense of peace and serenity. Blue topaz is also associated with wisdom and understanding, and it is often used in meditation and spiritual practices to enhance intuition and insight.
In ancient times, blue topaz was believed to have protective properties and was used in amulets and talismans to ward off negative energy and illness. It was also believed to enhance the powers of love and friendship and to strengthen relationships between people.
Care and Cleaning of the December Birthstones
Proper care and cleaning are essential for preserving the beauty and longevity of December birthstones. Each gemstone has specific care requirements based on its hardness, porosity, and sensitivity to light and chemicals.
Turquoise
Turquoise is a soft and porous gemstone that is easily damaged by water, oils, and chemicals. It should be cleaned gently with a soft cloth and mild soap and water. It should be stored in a cool, dry place away from direct sunlight and harsh chemicals. Turquoise should not be worn in water or exposed to perspiration for extended periods, as this can cause discoloration and deterioration.
Zircon
Zircon is more durable than turquoise but still requires careful handling. It should be cleaned with a soft cloth and mild soap and water. Zircon should not be exposed to high heat or light for extended periods, as this can cause the color to fade. It should be stored in a cool, dark place and kept separate from harder gemstones to prevent scratches.
Tanzanite
Tanzanite is sensitive to heat and light and should be cleaned gently with a soft cloth and mild soap and water. It should not be exposed to direct sunlight or artificial light for long periods, as this can cause the color to fade. Tanzanite should also be kept away from harsh chemicals and should be stored in a cool, dark place to maintain its color and clarity.
Blue Topaz
Blue topaz is one of the hardest December birthstones and is more resistant to scratches and damage. It can be cleaned with a soft cloth and mild soap and water or with an ultrasonic cleaner. Blue topaz is not sensitive to light and can be worn in most environments without fear of fading or damage. It should be stored in a cool, dry place and kept away from harder gemstones to prevent scratches.
Conclusion
The December birthstones—turquoise, tanzanite, zircon, and blue topaz—represent a diverse and fascinating selection of gemstones with rich histories, unique properties, and enduring appeal. From the ancient traditions of turquoise and zircon to the modern discovery of tanzanite and the vibrant color of blue topaz, these gemstones offer something for every December-born individual.
Each gemstone carries with it a legacy of cultural significance, geological rarity, and symbolic meaning, making them not only beautiful but also meaningful choices for jewelry and personal adornment. Whether you prefer the deep blue of turquoise, the violet-blue of tanzanite, the brilliant fire of zircon, or the clear brilliance of blue topaz, there is a December birthstone to suit every taste and occasion.
As with all gemstones, it is important to care for these stones properly to maintain their beauty and value. By understanding their properties and history, you can make an informed choice and appreciate the significance of these December birthstones for generations to come.