December 20th is a unique date in the world of birthstones, as it is associated with three distinct gemstones: Turquoise, Tanzanite, and Zircon, particularly blue zircon. Each of these gemstones carries its own set of historical, cultural, and gemological significance, making December a month of rich symbolism and diversity in the gemstone world. This article provides an in-depth exploration of the birthstones for December 20th, focusing on their meanings, properties, historical contexts, and how they are used in jewelry.
Introduction
The birthstone for those born on December 20th is a subject of some complexity due to the presence of three officially recognized gemstones: Turquoise, Tanzanite, and Zircon (specifically the blue variety). This multiplicity is unique and reflects the evolving nature of birthstone lists over time. The earliest known lists, inspired by biblical references, originally assigned ruby to December, but the modern list has undergone several changes, particularly in the 20th century, when tanzanite was added in 2002. Today, turquoise remains the most consistent and historically significant of the three, while tanzanite and blue zircon have added to the diversity and appeal of December's gemstone legacy.
The December 20th birthstone is more than just a decorative object—it is a symbol of protection, balance, and personal expression. These gemstones are valued not only for their beauty but also for their deep cultural and spiritual significance across different civilizations.
History and Lore
Turquoise: A Stone of Ancient Significance
Turquoise is one of the oldest known gemstones, with a history that spans thousands of years. The name "turquoise" comes from the French phrase pierre turquoise, meaning "Turkish stone," as it was introduced to Europe through Turkey. However, the stone itself has origins in Persia (modern-day Iran) and was also highly prized in Egypt, China, and the American Southwest.
In ancient Egypt, turquoise was considered a sacred stone and was often used in jewelry and amulets. It was associated with the gods and was believed to offer protection and divine favor. Pharaohs and other high-ranking individuals were often buried with turquoise artifacts, underscoring its importance in funerary practices.
In the American Southwest, particularly among the Navajo and Pueblo tribes, turquoise was used in ceremonial objects and jewelry. It was believed to bring good fortune, health, and spiritual protection. The stone was often combined with silver, a combination that remains popular in Native American jewelry to this day.
During the 19th century, turquoise gained popularity in Europe and the United States, largely due to the influence of Tiffany & Co., which began promoting it as a fashionable gemstone. By the early 20th century, turquoise had become firmly established as a December birthstone, a status it has maintained with only minor changes to the list over time.
Tanzanite: A Modern Discovery
Tanzanite is a far more recent addition to the December birthstone list, having been officially recognized in 2002. The discovery of tanzanite was a relatively recent event in the world of gemology. In 1967, Maasai tribesmen in Tanzania stumbled upon a deposit of bluish-violet crystals in the foothills of Mount Kilimanjaro. These crystals were initially thought to be sapphires, but further analysis revealed them to be a new and distinct variety of zoisite.
The crystals were brought to Manuel d’Souza, a prominent gem dealer, who then shared them with Tiffany & Co. The company saw the potential of the gem and launched an aggressive marketing campaign, which included renaming the gem "tanzanite" to reflect its origin in Tanzania. The name "tanzanite" was chosen not only to honor the country but also to avoid any negative connotations that might arise from the original name, which was considered too close to the word "suicide."
Tanzanite quickly became a popular gemstone, and in 2002, it was officially added to the list of December birthstones by the Jewelers of America. Its vibrant blue-violet color and relative rarity have made it a favorite among gemstone collectors and jewelry designers alike.
Zircon: A Stone of Timeless Beauty
Zircon, particularly the blue variety, has also been recognized as a December birthstone. Zircon is one of the oldest minerals on Earth, with some zircon crystals dating back over 4 billion years. The blue coloration in zircon is the result of heat treatment, a process that enhances the gemstone's color and clarity.
Zircon has been known and used in jewelry for centuries, though it was often confused with cubic zirconia—a synthetic gemstone with a similar name but different properties. Blue zircon, in particular, has gained popularity as a more affordable alternative to tanzanite and is valued for its brilliant luster and vibrant color.
The inclusion of zircon in the December birthstone list reflects the growing recognition of treated gemstones and the appreciation for the wide range of colors and properties that gemstones can exhibit when enhanced through heat treatment.
Geological Formation and Sources
Turquoise: A Product of Alkaline Environments
Turquoise is a phosphate mineral with the chemical formula CuAl₆(PO₄)₄(OH)₈·4H₂O. It forms in alkaline environments, typically in the weathering zones of copper deposits. The stone is composed of copper, aluminum, and phosphorus, and its characteristic blue-green color comes from the presence of copper.
Turquoise is most commonly found in desert regions, where the dry climate helps preserve the stone. Major sources of turquoise include:
- Iran (Persia) – the historical source of the finest turquoise
- Egypt – known for its use in ancient Egyptian jewelry
- China – where turquoise has been used in jade-like carvings
- United States – particularly in Arizona, New Mexico, and Nevada, where turquoise is mined and used in Native American jewelry
- Tanzania – where turquoise is also found, though less prominently than the other stones discussed
Turquoise is often treated to enhance its color and durability. Common treatments include stabilization with resin or oil, which can help prevent the stone from drying out and cracking.
Tanzanite: A Unique Zoisite Variety
Tanzanite is a trigonal mineral and a variety of zoisite, with the chemical formula Ca₂Al₃(SiO₄)(OH)₃(OH). The gemstone is known for its trichroic nature, meaning it can exhibit three different colors depending on the angle of light: blue, violet, and brown. The blue-violet color is the most desirable and is enhanced through heat treatment, which removes the brown tones.
Tanzanite is only found in one place in the world: Merelani Hills in Tanzania, near the base of Mount Kilimanjaro. This exclusivity makes tanzanite a rare and valuable gemstone. The Merelani mine is the only known source of tanzanite, and the gemstone is expected to become increasingly rare over time due to limited mining operations.
Zircon: A Versatile and Ancient Mineral
Zircon is a zirconium silicate with the chemical formula ZrSiO₄. It is a metamorphic mineral that forms in granitic rocks and is often found in placer deposits. The blue color in zircon is the result of heat treatment, which alters the crystal structure and enhances the gemstone's color.
Zircon is found in many parts of the world, including:
- Australia – a major source of zircon
- India – known for its high-quality zircon deposits
- Brazil – where zircon is often found in alluvial deposits
- Myanmar (Burma) – a traditional source of zircon
- Thailand – where zircon is cut and polished for the international market
Zircon is known for its high refractive index, which gives it a brilliant luster and makes it an excellent alternative to more expensive gemstones like sapphire and tanzanite.
Gemological Properties
Turquoise: A Soft and Colorful Gemstone
Turquoise is a relatively soft gemstone with a Mohs hardness of 5 to 6, which means it is susceptible to scratches and damage if not properly cared for. It is also porous, which means it can absorb oils and dirt over time. The color of turquoise can vary from deep blue to green, depending on the proportions of copper and iron in the stone.
The transparency of turquoise is usually opaque, though some varieties can be translucent. It is often cut into cabochons rather than facets, as its softness makes it unsuitable for faceting. The luster of turquoise is typically waxy or greasy, and it is often treated with oil or resin to enhance its color and durability.
Tanzanite: A Vibrant and Rare Gemstone
Tanzanite is a relatively soft gemstone with a Mohs hardness of 6 to 7, which means it is somewhat durable but still requires careful handling. It is trichroic, meaning it can exhibit three different colors depending on the angle of light. The most desirable color is the blue-violet variety, which is enhanced through heat treatment.
Tanzanite has a high refractive index, which gives it a brilliant luster and makes it ideal for faceting. It is often cut into emerald or cushion shapes to showcase its color and clarity. Tanzanite is also known for its pleochroism, which means it can show different colors from different angles.
Zircon: A Brilliant and Colorful Gemstone
Zircon is a harder gemstone than turquoise or tanzanite, with a Mohs hardness of 6.5 to 7.5, which makes it more suitable for everyday wear. It is known for its high refractive index, which gives it a brilliant luster and makes it an excellent alternative to diamonds and sapphires.
Zircon is often heat-treated to enhance its color, and the most popular variety is the blue zircon, which is used in December birthstone jewelry. Zircon can be cut into a variety of shapes, including round, emerald, and princess cuts, and it is often used in ring settings and necklaces.
Symbolism and Metaphysical Beliefs
Turquoise: A Stone of Protection and Balance
Turquoise has long been associated with protection, balance, and spiritual harmony. In many cultures, it is believed to absorb negative energy and promote positive change. It is also thought to enhance communication and self-expression, making it a popular stone for those who wish to speak their truth and express their emotions.
In ancient Egypt, turquoise was considered a protective stone, and it was often used in amulets and charms to ward off evil spirits. In the American Southwest, it was used in ceremonial objects and was believed to bring health, prosperity, and spiritual guidance.
Modern metaphysical beliefs associate turquoise with the Throat Chakra, which is responsible for communication and truth. It is believed to help align the body's energy centers, promoting inner balance and emotional stability.
Tanzanite: A Stone of Transformation and Clarity
Tanzanite is often associated with transformation, emotional healing, and spiritual awakening. It is believed to help individuals let go of the past and embrace new beginnings. Tanzanite is also thought to enhance intuition and psychic abilities, making it a popular stone for spiritual seekers and healers.
In modern metaphysical practices, tanzanite is used to promote emotional healing and inner peace. It is believed to help individuals release negative emotions and embrace their true selves. Tanzanite is also associated with the Throat and Third Eye Chakras, which are responsible for communication and insight.
Zircon: A Stone of Clarity and Energy
Zircon, particularly the blue variety, is believed to enhance clarity, energy, and emotional balance. It is often used in spiritual practices to promote mental focus and emotional stability. Zircon is also thought to protect against negative energies and to enhance the wearer’s connection to their higher self.
In modern metaphysical beliefs, zircon is associated with the Heart and Throat Chakras, which are responsible for love, communication, and emotional expression. It is believed to help individuals express their emotions and communicate their needs more effectively.
Care and Cleaning
Turquoise: Delicate and Porous
Due to its softness and porosity, turquoise requires special care to maintain its beauty and durability. It should be stored separately from harder gemstones to prevent scratches, and it should be avoided contact with harsh chemicals, as these can damage the stone’s surface.
To clean turquoise, use a soft cloth and mild soap, and avoid using ultrasonic or steam cleaners, as these can damage the stone’s structure. It is also a good idea to avoid exposing turquoise to excessive heat or direct sunlight, as these can cause it to fade or lose its luster.
Tanzanite: Sensitive to Heat and Pressure
Tanzanite is sensitive to heat and pressure, so it should be handled with care. It should be stored separately from other gemstones, and it should be avoided contact with harsh chemicals, as these can damage the stone’s color and structure.
To clean tanzanite, use a soft cloth and mild soap, and avoid using ultrasonic or steam cleaners, as these can damage the stone’s structure. It is also a good idea to avoid exposing tanzanite to excessive heat or direct sunlight, as these can alter its color or cause it to fade.
Zircon: Durable but Sensitive to Radiation
Zircon is more durable than turquoise or tanzanite, but it is sensitive to radiation, so it should be handled with care. It should be stored separately from other gemstones, and it should be avoided contact with harsh chemicals, as these can damage the stone’s color and structure.
To clean zircon, use a soft cloth and mild soap, and avoid using ultrasonic or steam cleaners, as these can damage the stone’s structure. It is also a good idea to avoid exposing zircon to excessive heat or direct sunlight, as these can alter its color or cause it to fade.
Conclusion
The birthstone for December 20th is a unique and diverse selection of gemstones, including turquoise, tanzanite, and blue zircon. Each of these gemstones carries its own set of historical, cultural, and gemological significance, making December a month of rich symbolism and beauty.
Turquoise, with its ancient roots and protective properties, remains the most historically significant of the three. Tanzanite, a modern discovery with a vibrant blue-violet color, adds to the rarity and appeal of December’s gemstone legacy. Blue zircon, a brilliant and affordable alternative, offers a versatile and colorful option for those who love the look of more expensive gemstones.
Whether you are drawn to the protection and balance of turquoise, the transformation and clarity of tanzanite, or the brilliance and energy of zircon, the December 20th birthstone offers something for everyone. These gemstones are not only beautiful but also carry deep cultural and spiritual significance, making them a meaningful choice for jewelry and personal adornment.
As the December 20th birthstone continues to be celebrated around the world, it serves as a reminder of the enduring connection between gemstones and human history, culture, and spirituality. Whether worn as a ring, necklace, or bracelet, the December 20th birthstone is a testament to the beauty and significance of gemstones in our lives.