December, the final month of the year, is uniquely distinguished in the realm of birthstones by boasting four officially recognized gems: turquoise, tanzanite, blue zircon, and blue topaz. These gemstones, all characterized by their cool blue hues, reflect the winter season and have been cherished for their beauty, rarity, and symbolic meanings. This article explores the history, gemological properties, cultural significance, and care instructions for each of these December birthstones, offering a comprehensive and authoritative guide for gemstone enthusiasts and jewelry connoisseurs alike.
Introduction
The tradition of associating gemstones with specific months dates back to ancient times, with roots in Mesopotamia and later adopted by the Greeks and Romans. Over time, the list of birthstones has evolved, influenced by new discoveries, commercial interests, and cultural practices. December’s birthstone selection has expanded significantly in the 20th century, starting with only turquoise and zircon and later including blue topaz and tanzanite. This evolution highlights the dynamic nature of the birthstone tradition and the growing appreciation for new gemstone varieties.
The four December birthstones—turquoise, tanzanite, blue zircon, and blue topaz—each have their own unique stories, from their geological origins and historical uses to their symbolic meanings and modern popularity. Despite their shared blue color palette, these stones differ in composition, rarity, and durability, making them suitable for a range of jewelry applications and personal preferences.
History and Lore
Turquoise
Turquoise is one of the oldest known gemstones, with a history that spans thousands of years. The name "turquoise" comes from the 17th-century French phrase "Pierre turquoise," meaning "Turkish stone," a reference to the trade routes that brought the gem to Europe from Turkey. However, turquoise was not originally mined in Turkey. Instead, it was formed in arid regions where copper, aluminum, and phosphate accumulate in rock cracks over time due to the flow of water.
Ancient civilizations, including the Egyptians, Persians, and Native Americans, highly valued turquoise for its beauty and believed it possessed protective and healing properties. In some cultures, men would present turquoise as a symbol of affection, while others used it in religious and ceremonial contexts. The stone's blue and green hues, influenced by copper and iron, were seen as reflections of the sky and earth, reinforcing its spiritual significance.
Tanzanite
Tanzanite, the newest of December’s birthstones, was discovered in 1967 in Tanzania, from which it takes its name. It is a variety of the mineral zoisite and is known for its remarkable trichroism—appearing blue, purple, or burgundy depending on the viewing angle. Tanzanite quickly gained popularity due to its rarity and striking color. It is mined exclusively in a small area near Mount Kilimanjaro, making it one of the most exclusive gemstones in the world.
Tanzanite was officially recognized as a December birthstone in 2002, adding to the existing list of turquoise and zircon. Its discovery and subsequent commercialization reflect the ongoing evolution of the birthstone tradition, as new gemstones are introduced based on their aesthetic appeal and market potential.
Blue Zircon
Zircon, a mineral with a long history, has been known and used in jewelry for centuries. Blue zircon, a popular variety, is typically color-enhanced through heat treatment, which transforms its natural color into a vibrant blue. Zircon was added to the December birthstone list in 1952, expanding the selection to include a gemstone that combines beauty with durability.
Historically, zircon was often confused with other gemstones, including topaz and cubic zirconia. However, its distinct refractive properties and color make it easily identifiable to gemologists. Blue zircon is particularly valued for its brilliance and clarity, making it a favored choice for those who appreciate a gemstone that sparkles like a diamond.
Blue Topaz
Blue topaz is a relatively modern addition to the December birthstone list, included in the 20th century. It is the hardest of the four December birthstones, ranking at 8 on the Mohs hardness scale. This durability makes it an excellent choice for everyday wear, particularly in rings and other frequently used jewelry pieces.
The exact historical origin of blue topaz is unknown, as it has been found in various locations throughout history. Today, it is mined in countries such as Sri Lanka, Brazil, Mexico, Nigeria, and the United States. Blue topaz was officially recognized as a December birthstone in the 1912 standardization by the National Association of Jewelers and has since become a popular and affordable option for December birthdays.
Geological Formation and Sources
Turquoise
Turquoise is a hydrated phosphate of aluminum and copper. It forms in arid environments where water percolates through rocks, depositing copper, aluminum, and phosphate in open spaces and cracks. Over time, these elements combine to create the distinctive blue and green hues of turquoise. The presence of iron can also influence the color, resulting in greenish tones.
Major sources of turquoise include Iran, the United States (particularly in Arizona and New Mexico), Egypt, and China. The quality and color of turquoise can vary significantly depending on the deposit, with some stones exhibiting deep blue tones and others displaying more muted or greenish hues. The presence of matrix—visible veins of surrounding rock—can also affect the stone's appearance and value.
Tanzanite
Tanzanite is a type of zoisite that contains vanadium, which is responsible for its blue and purple coloration. It is found exclusively in a small area near Mount Kilimanjaro in Tanzania, making it one of the rarest gemstones in the world. The geological conditions required for tanzanite to form are unique to this region, further contributing to its scarcity.
The mining of tanzanite is carefully regulated to ensure the sustainability of the resource. Due to its limited source and the ongoing depletion of existing deposits, tanzanite is expected to become even rarer in the future, increasing its value and desirability.
Blue Zircon
Zircon is a naturally occurring mineral that can be found in a variety of colors, including colorless, yellow, red, and brown. Blue zircon, the most popular variety, is typically produced through heat treatment, which enhances its natural color. The mineral forms in igneous and metamorphic rocks and is found in many parts of the world, including Australia, Brazil, and Madagascar.
Blue zircon is known for its brilliance and refractive index, which gives it a diamond-like sparkle. It is also relatively durable, with a hardness of 6.5 to 7.5 on the Mohs scale. This makes it suitable for a range of jewelry applications, although it should be handled with care to avoid scratches and chips.
Blue Topaz
Blue topaz is a silicate mineral that is typically colorless in its natural state. The blue coloration is achieved through irradiation and heat treatment, which alter the mineral's structure and create the desired hue. Blue topaz is found in several countries, including Brazil, Sri Lanka, and Nigeria, with the United States also being a significant source.
The hardness of blue topaz (8 on the Mohs scale) makes it highly durable and suitable for everyday wear. It is often used in rings, pendants, and earrings, where its brilliance and clarity can be fully appreciated. The availability of blue topaz in a range of sizes and qualities makes it a versatile and accessible gemstone for December birthdays.
Gemological Properties
Turquoise
Turquoise is a soft gemstone, with a hardness of 5 to 6 on the Mohs scale. It is relatively porous and can absorb liquids and oils, which can affect its color and appearance over time. The stone is often stabilized with resins or waxes to enhance its durability and prevent cracking.
Color: Blue to green, with variations due to the presence of copper and iron.
Hardness: 5–6 on the Mohs scale.
Luster: Waxy to greasy.
Transparency: Opaque to translucent.
Chemical Composition: Hydrated phosphate of aluminum and copper (Al₂(OH)PO₄).
Tanzanite
Tanzanite is a relatively soft gemstone, with a hardness of 6 to 7 on the Mohs scale. It is also sensitive to heat and light, which can cause fading or discoloration. Care must be taken to avoid exposing tanzanite to high temperatures or prolonged sunlight.
Color: Blue, purple, and burgundy (trichroic).
Hardness: 6–7 on the Mohs scale.
Luster: Vitreous.
Transparency: Translucent to transparent.
Chemical Composition: Calcium aluminum silicate with vanadium (Ca₂Al₃(SiO₄)₃(OH)).
Blue Zircon
Blue zircon is a durable gemstone, with a hardness of 6.5 to 7.5 on the Mohs scale. It is known for its high refractive index and dispersion, which contribute to its brilliance and fire.
Color: Blue (after heat treatment).
Hardness: 6.5–7.5 on the Mohs scale.
Luster: Vitreous.
Transparency: Transparent.
Chemical Composition: Zirconium silicate (ZrSiO₄).
Blue Topaz
Blue topaz is one of the hardest December birthstones, with a hardness of 8 on the Mohs scale. It is highly resistant to scratches and is suitable for everyday wear.
Color: Blue (after irradiation and heat treatment).
Hardness: 8 on the Mohs scale.
Luster: Vitreous.
Transparency: Transparent.
Chemical Composition: Aluminum silicate (Al₂SiO₆).
Symbolism and Metaphysical Beliefs
Turquoise
Turquoise has long been associated with protection, good fortune, and spiritual growth. In many cultures, it is believed to have healing properties and is used to promote calmness and balance. The stone is also associated with communication and self-expression, making it a popular choice for those who wish to enhance their ability to speak and be heard.
In ancient Egypt, turquoise was used in amulets and burial masks, believed to protect the wearer in the afterlife. Native American tribes, particularly the Navajo and Zuni, used turquoise in jewelry and ceremonial objects, seeing it as a symbol of life and vitality.
Tanzanite
Tanzanite is associated with transformation, growth, and new beginnings. Its blue-violet color is said to reflect the clarity and curiosity needed to embrace change and step into new chapters of life. The stone is also believed to promote emotional balance and understanding, helping individuals navigate complex emotions and relationships.
Tanzanite is often used in meditation and spiritual practices, where it is thought to enhance intuition and psychic abilities. It is also a popular choice for those seeking to align their chakras and promote inner harmony.
Blue Zircon
Blue zircon is associated with clarity, wisdom, and a sense of balance. It is believed to sharpen mental focus and enhance decision-making abilities. The stone is also associated with prosperity and success, making it a popular choice for those pursuing career or business goals.
In ancient times, zircon was believed to have protective properties and was used to ward off negative energies. Today, it is often used in jewelry as a symbol of strength and resilience.
Blue Topaz
Blue topaz is associated with calmness, clarity, and emotional balance. It is believed to promote inner peace and serenity, making it an excellent choice for those seeking to reduce stress and anxiety. The stone is also associated with love and friendship, making it a popular choice for gifts and sentimental jewelry.
Blue topaz is often used in crystal healing practices, where it is thought to enhance communication and encourage honesty and truth. It is also believed to support the body's natural healing processes and promote overall well-being.
Care and Cleaning
Turquoise
Due to its softness and porosity, turquoise requires special care to maintain its appearance. It should be kept away from harsh chemicals, perfumes, and lotions, which can cause discoloration or damage. The stone should be stored separately from other gemstones to avoid scratches.
Cleaning: Gently wipe with a soft, damp cloth. Avoid soaking in water or using ultrasonic cleaners.
Storage: Store in a dry, cool place, preferably in a soft pouch or lined box.
Tanzanite
Tanzanite is sensitive to heat and light and should be protected from prolonged exposure to direct sunlight or high temperatures. It is also relatively soft, so it should be handled with care to avoid scratches and chips.
Cleaning: Use a soft, damp cloth to gently wipe the stone. Avoid ultrasonic cleaners and steam cleaning.
Storage: Store in a cool, dark place to prevent fading.
Blue Zircon
Blue zircon is relatively durable but should be handled with care to avoid scratches and chips. It can be cleaned with warm, soapy water and a soft cloth.
Cleaning: Soak in warm, soapy water, then gently wipe with a soft cloth. Avoid using harsh chemicals or ultrasonic cleaners.
Storage: Store in a cool, dry place, preferably in a soft pouch or lined box.
Blue Topaz
Blue topaz is one of the hardest December birthstones and can be cleaned using standard jewelry cleaning methods. However, it should be kept away from harsh chemicals and abrasive materials.
Cleaning: Use warm, soapy water and a soft cloth. Ultrasonic and steam cleaners can also be used.
Storage: Store in a cool, dry place, preferably in a soft pouch or lined box.
Conclusion
December’s four birthstones—turquoise, tanzanite, blue zircon, and blue topaz—each offer a unique combination of beauty, history, and symbolism. From the ancient and storied turquoise to the rare and modern tanzanite, these gemstones reflect the evolving nature of the birthstone tradition and the enduring appeal of blue gemstones. Whether you prefer the soft, pastel hues of turquoise, the deep, shifting blues of tanzanite, the brilliant sparkle of blue zircon, or the crisp clarity of blue topaz, there is a December birthstone to suit every taste and style. Understanding the properties, care, and symbolism of these gemstones allows you to choose the perfect stone to celebrate the winter month and honor the traditions that have been passed down through generations.