December is a month marked by the cool, tranquil blues of its birthstones—blue topaz, blue zircon, tanzanite, and turquoise. These gemstones, each with its own unique history, composition, and symbolism, reflect the diverse allure of December’s gemstone legacy. From the vibrant blue of tanzanite to the soft, earthy tones of turquoise, these stones have captivated people for centuries and continue to do so today.
This article explores the rich history, geological origins, gemological properties, and cultural significance of each of these December birthstones. Whether you're drawn to the elegance of blue topaz, the rarity of tanzanite, the mystique of zircon, or the ancient charm of turquoise, this guide will provide a comprehensive understanding of what makes these stones special.
History and Lore
The concept of birthstones dates back thousands of years, with early references appearing in ancient texts such as the Breastplate of Aaron in the Bible. These stones were believed to offer protection, health, and spiritual connection. Over time, the list of birthstones has evolved, and today, December is uniquely represented by four distinct stones.
Blue Topaz: A Modern Classic
Blue topaz is a relatively recent addition to the birthstone list. While topaz has been known since antiquity—being mentioned in the Bible and prized by the ancients for its beauty—its blue variety was only developed through modern heat treatments and irradiation in the 20th century. This transformation allowed blue topaz to become a popular and affordable alternative to more expensive blue gemstones like sapphire. Its vibrant blue color and durability have made it a favorite in contemporary jewelry design.
Blue Zircon: A Hidden Treasure
Blue zircon has a long and storied history, though it is less well-known than some of its counterparts. Zircons have been used in jewelry for centuries, with some of the oldest known zircon gems dating back to ancient Egypt and Mesopotamia. The blue variety, in particular, gained popularity in the 20th century after being heat-treated to enhance its color. Blue zircon is often mistaken for blue sapphire due to its similar color, but its unique refractive properties and hardness distinguish it as a gem in its own right.
Tanzanite: A 20th-Century Discovery
Tanzanite is the youngest of December’s birthstones, having been discovered in 1967 in the Merelani Hills of Tanzania. It was originally identified as a type of zoisite, but its stunning blue-violet color led to its reclassification as a distinct gemstone. Tanzanite’s discovery was a major milestone in the gemstone world, and it quickly gained international recognition thanks to a major marketing campaign led by Tiffany & Co. in 1968. Because it is found only in Tanzania, tanzanite is considered one of the rarest and most exclusive gemstones in the world.
Turquoise: An Ancient Gem
Turquoise has perhaps the most ancient and culturally significant history of all the December birthstones. Its use dates back over 5,000 years, with archaeological evidence of its use in jewelry and ornaments found in ancient Egypt, Persia, and the Americas. Turquoise was highly valued for its protective and spiritual properties, and it was believed to bring good fortune, health, and prosperity. In many indigenous cultures, turquoise is still considered a sacred stone and is used in ceremonial jewelry and artifacts.
The inclusion of turquoise as a December birthstone reflects its long-standing role in human history and its enduring appeal. Unlike the other December stones, which are relatively modern in their recognition as birthstones, turquoise has a rich tradition that spans millennia.
Geological Formation and Sources
The four December birthstones originate from different geological processes and are found in various parts of the world. Understanding their formation and sources helps to appreciate their rarity and beauty.
Blue Topaz: A Versatile Gem
Topaz is a silicate mineral that forms in igneous rocks such as granite and rhyolite. It is known for its hardness and clarity, with blue topaz being one of the most popular varieties. The blue color in topaz is typically the result of irradiation and heat treatment, which alters the stone's natural color. Natural blue topaz is rare, so most of the blue topaz available on the market is enhanced through these methods.
Topaz is found in several countries, including Brazil, Mexico, the United States, and Nigeria. Brazil is the largest producer of topaz, with significant deposits in the state of Minas Gerais. The availability of topaz in these regions makes it a more accessible and affordable option for jewelry.
Blue Zircon: A Colorful Transformation
Zircon is a zirconium silicate that can occur in a wide range of colors, including brown, yellow, red, and blue. The blue variety is particularly popular as a birthstone due to its brilliant fire and vibrant color. Natural blue zircon is rare, so most of the blue zircon on the market is heat-treated to enhance its color. This treatment is stable and permanent, making blue zircon a durable and attractive gemstone.
Zircon is found in several countries, including Cambodia, Sri Lanka, and Madagascar. Cambodia is a major source of blue zircon, and the gem has become a signature stone of the region. The presence of zircon in these areas has contributed to its growing popularity in the jewelry industry.
Tanzanite: A Unique Geological Phenomenon
Tanzanite is a rare gemstone that is found exclusively in the Merelani Hills of Tanzania. It forms in metamorphic rocks, where the mineral zoisite is subjected to high heat and pressure, resulting in its characteristic blue-violet color. The conditions required for tanzanite to form are extremely specific, which is why it is only found in this one location.
The Merelani Hills are located in northern Tanzania, near the base of Mount Kilimanjaro. The area is known for its rich gemstone deposits and has become a major mining region. Tanzanite is often found in association with other minerals, and careful extraction is required to preserve the integrity of the stone. Because of its limited source and increasing demand, tanzanite is considered one of the most valuable and sought-after gemstones in the world.
Turquoise: A Product of Nature’s Alchemy
Turquoise is a hydrated phosphate of copper and aluminum. It forms when copper-rich water seeps through porous rock, reacting with aluminum and other minerals to create the distinctive blue-green color of turquoise. This process typically occurs in arid regions where there is minimal rainfall, allowing the water to evaporate and leave behind the turquoise deposits.
The most famous sources of turquoise are in the southwestern United States, particularly in Arizona, New Mexico, and Nevada. Other notable sources include Iran, China, and Egypt. Each location produces turquoise with slightly different colors and matrix patterns, making each piece unique. Turquoise from the United States is highly prized for its bright blue color and minimal matrix, while turquoise from Iran is known for its deep green hues.
Gemological Properties
Understanding the gemological properties of December’s birthstones is essential for both jewelers and collectors. These properties include hardness, refractive index, chemical composition, and color stability, all of which affect the stone’s durability and appearance.
Blue Topaz: A Hard and Stable Gem
Blue topaz has a hardness of 8 on the Mohs scale, making it one of the harder December birthstones. It is also highly stable and resistant to scratches, which makes it suitable for everyday wear in jewelry. Its refractive index ranges from 1.61 to 1.63, giving it a bright, clear appearance. Because of its durability and affordability, blue topaz is a popular choice for rings, pendants, and earrings.
Blue Zircon: A Sparkling Enigma
Blue zircon has a hardness of 6 to 7.5 on the Mohs scale, which means it is somewhat softer than blue topaz. It is known for its high refractive index and dispersion, which give it a brilliant, fiery sparkle. However, some blue zircons may revert to their natural color (usually brown) after prolonged exposure to bright light. This is due to the heat treatment used to enhance their color. Despite this, blue zircon remains a popular gemstone for its beauty and affordability.
Tanzanite: A Delicate Beauty
Tanzanite has a hardness of 6 to 7 on the Mohs scale, which makes it a relatively delicate gemstone. It is also sensitive to heat and light, and prolonged exposure can cause it to fade or change color. Tanzanite has a high refractive index and a moderate dispersion, which gives it a "velvety" appearance. Because of its sensitivity, it is best suited for jewelry that is worn occasionally rather than daily.
Turquoise: A Soft and Porous Stone
Turquoise is a relatively soft gemstone with a hardness of 5 to 6 on the Mohs scale. It is also porous and easily stained, which means it requires careful handling and cleaning. Turquoise is often treated with oils or resins to improve its durability and appearance. Because of its softness, it is best suited for jewelry that is worn less frequently, such as pendants or earrings.
Symbolism and Metaphysical Beliefs
The December birthstones are not only prized for their beauty but also for their rich symbolism and metaphysical properties. These beliefs have been passed down through generations and continue to influence the way people view and use these gemstones.
Blue Topaz: A Stone of Calm and Clarity
Blue topaz is believed to promote calmness, clarity, and serenity. It is often associated with the throat chakra, which is linked to communication and self-expression. Some believe that blue topaz can help to soothe anxiety, enhance mental clarity, and encourage honest communication. It is also considered a stone of good fortune and is often used in jewelry to attract positive energy.
Blue Zircon: A Stone of Transformation and Hope
Blue zircon is associated with transformation, hope, and joy. It is believed to help the wearer release old patterns and embrace new beginnings. Some metaphysical traditions suggest that blue zircon can enhance spiritual insight and promote emotional healing. It is also thought to be a protective stone, shielding the wearer from negative energies.
Tanzanite: A Stone of Intuition and Empathy
Tanzanite is often linked to the heart and throat chakras, and is believed to enhance intuition, empathy, and self-expression. It is considered a stone of transformation and is used in meditation to promote emotional balance and spiritual growth. Some believe that tanzanite can help to dissolve emotional blockages and encourage compassion and understanding.
Turquoise: A Stone of Protection and Wisdom
Turquoise has been used for centuries as a protective and healing stone. It is believed to bring good luck, protect against illness, and promote longevity. In many indigenous cultures, turquoise is considered a sacred stone that connects the earth and sky. It is also associated with wisdom, clarity, and spiritual growth. Some believe that turquoise can help to calm the mind, enhance intuition, and promote emotional stability.
Care and Cleaning
Proper care and cleaning are essential for maintaining the beauty and longevity of December birthstones. Each stone has its own specific requirements based on its hardness, porosity, and sensitivity to light and chemicals.
Blue Topaz
Blue topaz is a durable gemstone that can be cleaned with warm, soapy water and a soft brush. It is resistant to scratches and can be worn daily. However, it is best to avoid exposing it to harsh chemicals or extreme temperatures, as this can affect its color and clarity.
Blue Zircon
Blue zircon is more delicate than blue topaz and requires careful handling. It should be cleaned with a mild soap and warm water, using a soft brush. Ultrasonic and steam cleaners are not recommended, as they can cause the stone to lose its color. It is best to avoid wearing blue zircon in rough conditions or when exposed to prolonged sunlight.
Tanzanite
Tanzanite is sensitive to heat and light and should be stored in a cool, dark place when not in use. It can be cleaned with warm, soapy water and a soft brush, but ultrasonic and steam cleaners should be avoided. It is best to wear tanzanite in jewelry that is worn occasionally rather than daily, to minimize exposure to heat and light.
Turquoise
Turquoise is a soft and porous stone that requires special care. It should be cleaned with a soft cloth and mild soap, and should never be exposed to harsh chemicals or excessive water. Because it is porous, it can absorb oils and dirt easily, so it is best to avoid wearing it in humid or oily environments. Turquoise is often treated with oils or resins to enhance its durability, so it is important to avoid using abrasive cleaners or harsh chemicals.
Conclusion
December’s birthstones—blue topaz, blue zircon, tanzanite, and turquoise—offer a stunning array of colors, histories, and properties that make them unique and valuable. From the vibrant blue of tanzanite to the soft hues of turquoise, these gemstones have captivated people for centuries and continue to do so today. Whether you are drawn to their beauty, their symbolism, or their rarity, these stones are a testament to the enduring allure of gemstones in human culture.
Each of these December birthstones has its own story to tell, from the ancient traditions surrounding turquoise to the modern discovery of tanzanite. Their geological origins, gemological properties, and cultural significance make them fascinating subjects for study and appreciation. Whether you choose one as a personal birthstone or simply admire them from afar, these stones are a reminder of the natural wonders that surround us.