December is one of the few months with more than one birthstone, offering a unique selection of gemstones that reflect the cold beauty and rich symbolism of the winter season. For those born on December 9, or anyone interested in the broader significance of December’s birthstones, the choices include turquoise, tanzanite, zircon, and blue topaz. Each of these gemstones carries its own distinct history, gemological properties, and cultural significance, making them not only beautiful but also deeply meaningful.
This article delves into the world of December birthstones, exploring their historical roots, geological origins, and the reasons they have become treasured symbols of the final month of the year. We will examine the lore and metaphysical beliefs surrounding each stone, as well as their practical characteristics such as hardness, color, and care requirements. By the end of this article, you will have a comprehensive understanding of what makes these gemstones special and how they continue to captivate jewelers, collectors, and December-born individuals alike.
History and Lore of December Birthstones
The tradition of associating gemstones with birth months has ancient roots, with the earliest references appearing in the Bible’s Book of Exodus, which lists twelve gemstones on the High Priest’s breastplate. These stones were believed to represent the twelve tribes of Israel and were imbued with spiritual power. Over time, these biblical references evolved into the modern birthstone calendar we know today, though the associations have shifted significantly.
December, named from the Latin word decem meaning “ten,” was once considered the tenth month in the ancient Roman calendar. Its birthstone tradition has undergone multiple changes over the centuries. The earliest recorded December birthstone was ruby, a gemstone of deep red and royal significance. However, as time passed and gemological knowledge advanced, other stones were added and substituted, reflecting the changing aesthetics and values of different eras.
The modern December birthstone list includes four gems: turquoise, tanzanite, zircon, and blue topaz. The inclusion of multiple birthstones for December reflects a broader trend in the 20th century, where the jewelry industry sought to expand the range of options available to consumers. This flexibility allows for greater personalization and affordability, as well as an appreciation for the diverse cultural and geological significance of each stone.
The evolution of December’s birthstones is marked by key milestones:
- 1870: Turquoise was designated as the December birthstone in Tiffany & Co.’s “Gregorian Birthstone Poems.”
- 1912: Turquoise remained the primary December birthstone, with lapis lazuli as an alternative, according to the National Association of Jewellers (now the Jewellers of America).
- 1952: Zircon was added to the list by the Jewelry Industry Council of America.
- 2002: Tanzanite, a newly discovered and highly marketable gemstone, was added to the December birthstone roster.
These additions highlight the dynamic nature of birthstone traditions and the influence of both historical precedent and modern market forces. Each of these gems has its own story to tell, and their inclusion in December’s birthstone list underscores the month’s rich symbolism of transition, celebration, and renewal.
Geological Formation and Sources of December Birthstones
Each of December’s birthstones has a unique geological profile, determined by the minerals from which they form and the conditions under which they are created. Understanding these origins not only enhances our appreciation for these gems but also informs their care and use in jewelry.
Turquoise
Turquoise is a phosphate of aluminum and copper, forming in arid environments where copper-rich veins intersect with the weathering of surrounding rocks. It is typically found in the oxidation zones of copper deposits, where water carries copper ions into the porous rock, reacting with phosphorus and aluminum to form the characteristic blue-green mineral.
Historically, turquoise has been mined in various parts of the world, including China, Egypt, Persia, and the Americas. Today, major sources include Iran, the United States (particularly Arizona and Nevada), and China. The color of turquoise can vary widely depending on the specific mineral composition and trace elements. For example, the presence of iron can deepen the blue hue, while the inclusion of yellow limonite creates the striking "spiderweb" patterns seen in some stones.
Turquoise is relatively soft, with a hardness of 5 to 6 on the Mohs scale, making it more susceptible to scratches and damage from moisture and chemicals. It is also porous, which means it can absorb oils and other substances, affecting its color and luster.
Tanzanite
Tanzanite is a relatively modern discovery, first identified in the late 1960s in Tanzania. It is a variety of the mineral zoisite, distinguished by its striking blue and violet hues, which are caused by the presence of vanadium. The gemstone is only found in a small area near the Mererani Hills, in the northern part of Tanzania, making it one of the rarest gemstones in the world.
The formation of tanzanite is tied to the geological history of the East African Rift. The mineral developed in metamorphic rock formations, where intense heat and pressure transformed existing minerals into new structures. Tanzanite is known for its strong trichroism, appearing in different colors—blue, violet, and brown—depending on the angle at which it is viewed.
Tanzanite is typically heat-treated to enhance its color, removing a brownish veil that can occur in raw material. This treatment is stable and permanent, making it a standard practice in the industry. Tanzanite has a hardness of 6 to 7 on the Mohs scale, making it relatively durable for jewelry use, though care should be taken to avoid exposure to harsh chemicals and high heat.
Zircon
Zircon is a complex silicate mineral that forms in a wide variety of geological environments, including igneous, sedimentary, and metamorphic rocks. It is known for its high refractive index and dispersion, which give it a brilliance that is often compared to that of diamonds. Zircon occurs in a range of colors, including colorless, yellow, red, green, and blue.
Blue zircon, one of the most popular varieties, is created through heat treatment that removes impurities and enhances the blue color. This treatment is stable and widely used in the jewelry industry. Zircon is found in several countries, including Thailand, Cambodia, and Vietnam, as well as in parts of Australia and India.
Zircon has a hardness of 6 to 7.5 on the Mohs scale, making it durable enough for everyday wear, though it is more susceptible to cleavage and chipping than harder gemstones like sapphires or diamonds. Its refractive properties make it a popular diamond simulant, especially in the colorless variety.
Blue Topaz
Blue topaz is a popular alternative to zircon and tanzanite in December birthstone jewelry. While natural blue topaz does exist, the majority of blue topaz on the market is created through irradiation and heat treatment, which enhance the blue color. The treatment is stable and permanent.
Topaz is a silicate mineral that forms in igneous rocks, particularly those rich in sodium. It is found in several countries, including Brazil, Nigeria, and the United States. Blue topaz is particularly abundant in Brazil, where large, high-quality stones are often mined.
Topaz has a hardness of 8 on the Mohs scale, making it one of the harder December birthstones. It is also resistant to scratches and can be worn daily with minimal risk of damage. However, like many gemstones, it should be kept away from harsh chemicals and extreme temperatures.
Gemological Properties of December Birthstones
Understanding the gemological properties of December’s birthstones is essential for appreciating their beauty and ensuring their proper care. Each gemstone has distinct characteristics that affect its appearance, durability, and suitability for different types of jewelry.
Turquoise
- Chemical Composition: Phosphate of aluminum and copper (Al₂(OH)PO₄)
- Hardness (Mohs Scale): 5 to 6
- Refractive Index: 1.61 to 1.65
- Specific Gravity: 2.6 to 2.8
- Color: Blue, green, and yellow
- Transparency: Opaque to translucent
- Luster: Waxy to greasy
- Cleavage: None
- Common Cuts: Cabochon
- Common Treatments: Stabilization with resin to enhance color and durability
Turquoise is known for its vibrant colors and unique patterns, but it is relatively soft and porous, which makes it more delicate than many other gemstones.
Tanzanite
- Chemical Composition: Calcium aluminum hydroxyl sorosilicate (Ca₂Al₃(SiO₄)(OH)₃) with vanadium
- Hardness (Mohs Scale): 6 to 7
- Refractive Index: 1.694 to 1.704
- Specific Gravity: 3.1 to 3.4
- Color: Blue, violet, and brown
- Transparency: Transparent to translucent
- Luster: Vitreous
- Cleavage: Poor
- Common Cuts: Oval, cushion
- Common Treatments: Heat treatment to enhance color
Tanzanite is prized for its deep, velvety blue and violet hues, which are enhanced through heat treatment. It is relatively durable, making it suitable for a variety to jewelry styles.
Zircon
- Chemical Composition: Zirconium silicate (ZrSiO₄)
- Hardness (Mohs Scale): 6 to 7.5
- Refractive Index: 1.92 to 2.00
- Specific Gravity: 4.6 to 4.7
- Color: Colorless, blue, yellow, red, green
- Transparency: Transparent to translucent
- Luster: Vitreous to subadamantine
- Cleavage: Poor
- Common Cuts: Round, emerald, princess
- Common Treatments: Heat treatment to enhance color
Zircon is known for its brilliance and dispersion, which give it a fire that rivals that of diamonds. Blue zircon is a popular alternative to diamonds and other precious gems.
Blue Topaz
- Chemical Composition: Aluminum silicate (Al₂SiO₄(F,OH)₂)
- Hardness (Mohs Scale): 8
- Refractive Index: 1.61 to 1.63
- Specific Gravity: 3.53
- Color: Blue
- Transparency: Transparent
- Luster: Vitreous
- Cleavage: Perfect
- Common Cuts: Round, princess, oval
- Common Treatments: Irradiation and heat treatment to enhance color
Blue topaz is a durable gemstone with a high hardness, making it ideal for everyday wear. It is also more affordable than tanzanite or zircon, making it a popular choice for birthstone jewelry.
Symbolism and Metaphysical Beliefs
December’s birthstones have been attributed with a range of symbolic meanings and metaphysical properties across different cultures and historical periods. These beliefs often reflect the gemstones’ natural characteristics and the values associated with the month of December.
Turquoise
Turquoise has long been regarded as a protective and healing stone. In ancient Egypt, it was used to adorn mummies and was believed to guide the soul to the afterlife. Native American cultures have also revered turquoise as a sacred stone, associating it with the sky, water, and the divine. It is often used in ceremonies and rituals to promote communication, clarity, and emotional balance.
In modern metaphysical practices, turquoise is believed to enhance self-expression, encourage honesty, and foster compassion. It is also said to provide protection from negative energy and promote a sense of calm and stability.
Tanzanite
Tanzanite is a relatively modern gemstone, but it has quickly become associated with transformation and emotional healing. Its deep blue and violet hues are thought to resonate with the heart and throat chakras, promoting emotional balance and spiritual growth.
In metaphysical circles, tanzanite is believed to help release old patterns, especially those related to fear and insecurity. It is also associated with intuition and the ability to see the future, making it a popular stone for meditation and dream work.
Zircon
Zircon has been used in jewelry for thousands of years, and its metaphysical properties are often linked to its brilliance and refractive qualities. In some traditions, zircon is believed to enhance mental clarity, intuition, and spiritual insight. It is also said to promote a sense of grounding and stability, helping to balance the mind and body.
Zircon is often used in meditation practices to enhance concentration and awareness. It is also associated with the idea of time, as some zircon crystals are among the oldest minerals on Earth.
Blue Topaz
Blue topaz is associated with calmness, communication, and emotional balance. It is believed to help soothe the mind and reduce stress, making it a popular stone for those who work in high-pressure environments or who are prone to anxiety.
In metaphysical practices, blue topaz is used to enhance communication and encourage honesty in relationships. It is also believed to promote wisdom and clarity of thought, making it a valuable tool for decision-making and problem-solving.
Care and Cleaning of December Birthstones
Proper care is essential for maintaining the beauty and longevity of December’s birthstones. Each gemstone has its own specific care requirements, based on its hardness, porosity, and susceptibility to damage.
Turquoise
- Avoid Moisture: Turquoise is porous and can absorb moisture, which may dull its color and luster. It should be stored in a dry environment, away from water.
- Avoid Chemicals: Exposure to household chemicals, perfumes, and lotions can damage the stone. Remove turquoise jewelry before applying any products.
- Avoid Heat: High heat can cause turquoise to lose its color or become brittle. Avoid exposing it to direct sunlight or heat sources.
- Cleaning: Gently wipe the stone with a soft, dry cloth. Do not use water or cleaning solutions.
Tanzanite
- Avoid Heat: Tanzanite can be heat-sensitive and may lose its color if exposed to high temperatures. Avoid placing it in direct sunlight or near heat sources.
- Avoid Chemicals: Tanzanite can be damaged by harsh chemicals, including household cleaners and perfumes. Remove jewelry before using any chemicals.
- Avoid Hard Impacts: While tanzanite is relatively durable, it can chip or crack if struck against a hard surface. Handle with care.
- Cleaning: Gently clean with a soft, damp cloth. Avoid using ultrasonic or steam cleaners, as they may damage the stone.
Zircon
- Avoid Heat: Zircon is sensitive to heat and may lose its color or become brittle. Avoid exposing it to high temperatures.
- Avoid Chemicals: Zircon can be damaged by harsh chemicals, so it is best to remove jewelry before using any products.
- Avoid Hard Impacts: Zircon has a tendency to cleave along its crystal structure, so it should be handled carefully to avoid chipping.
- Cleaning: Gently clean with a soft, damp cloth. Avoid using ultrasonic or steam cleaners.
Blue Topaz
- Avoid Chemicals: Blue topaz is relatively durable, but it can be damaged by harsh chemicals. Remove jewelry before using any products.
- Avoid Heat: High heat can affect the color of blue topaz. Avoid exposing it to direct sunlight or heat sources.
- Avoid Hard Impacts: While topaz is hard, it can still chip or crack if struck against a hard surface. Handle with care.
- Cleaning: Gently clean with a soft, damp cloth. Avoid using ultrasonic or steam cleaners.
Conclusion
December’s birthstones—turquoise, tanzanite, zircon, and blue topaz—offer a unique and beautiful selection of gemstones that reflect the cold, elegant charm of the winter season. Each of these stones has its own distinct history, geological properties, and symbolic meanings, making them not only beautiful but also deeply meaningful.
Turquoise has been revered for centuries for its protective and healing properties, while tanzanite is a modern gemstone that symbolizes transformation and emotional growth. Zircon is prized for its brilliance and refractive qualities, and blue topaz is a durable and affordable alternative that offers a beautiful blue hue.
Whether you are a December-born individual looking for a meaningful birthstone or a gemstone enthusiast seeking to expand your collection, these gems provide a rich tapestry of colors, histories, and meanings. With proper care and appreciation, they can be cherished for generations, serving as timeless symbols of elegance, individuality, and the enduring magic of December.