The tradition of associating specific gemstones with the months of the year is a practice steeped in millennia of history, evolving from ancient religious texts to modern commercial standards. While some months are defined by a single, iconic stone, others offer a diverse palette of choices, reflecting geological rarity, cultural shifts, and aesthetic preferences. December stands out as a month of remarkable variety, offering four distinct blue-hued gemstones: Turquoise, Tanzanite, Blue Topaz, and Blue Zircon. In contrast, February is anchored by the singular, regal presence of Amethyst. This article provides an in-depth exploration of these captivating birthstones, examining their geological origins, gemological properties, historical lore, and the practical considerations for their care and preservation.
The Evolution of Birthstone Associations
The concept of birthstones is not a modern invention but rather a tradition with deep historical roots. The earliest known reference dates back to the 1st century, as recorded by the historian Josephus, who drew a connection between the twelve stones in the breastplate of the Jewish High Priest and the twelve signs of the zodiac. This linkage was further developed in the 5th century by St. Jerome, who proposed a correspondence between the twelve stones and the twelve months of the year. These early lists, however, were fluid and often varied based on availability and cultural interpretation.
The modern birthstone chart, as recognized today, is largely a product of standardization efforts in the 19th and 20th centuries. In 1912, the National Association of Jewelers (now Jewelers of America) convened to create an official list to unify trade practices. This list has been updated several times, most notably to include new discoveries like Tanzanite for December. This evolution underscores a dynamic interplay between ancient tradition and the realities of the modern gem market, where new sources and discoveries can reshape long-held customs.
December's Azure Palette: A Quartet of Blue Gems
December is unique in the birthstone calendar for its lack of a single, universally accepted stone. Instead, it offers a spectrum of blue, from the opaque, earthy tones of turquoise to the vivid, saturated hues of tanzanite and topaz. This diversity allows those born in the final month of the year a wide range of choices in color, price, and durability.
Turquoise: The Ancient Talisman
Among the earliest of all gemstones to be mined and revered, Turquoise is an opaque mineral prized for its distinctive blue-to-green coloration. Its name is derived from the French "pierre turquoise," meaning "Turkish stone," a reference to the trade routes through which the stone reached Europe from mines in the Persian (now Iranian) plateau. However, its history extends far beyond the Silk Road.
History and Lore Turquoise has been a cornerstone of spiritual and decorative life for numerous ancient civilizations. In ancient Egypt, it was used to create intricate jewelry and amulets, with examples found in the tomb of Tutankhamun. The ancient Persians believed it represented the heavens on earth and worn it as a protective talisman against unnatural death, believing its color would change to warn of impending danger. In Mesoamerica, particularly for the Aztec and Maya civilizations, turquoise was a sacred stone, often used in elaborate mosaics and rituals to honor the gods. Its significance was so profound that it was often more valuable than gold.
Geological Formation and Sources Turquoise is a secondary mineral that forms when acidic, copper-rich waters percolate through aluminum-bearing rocks. This process occurs in arid regions, which explains its primary mining locations. Historically, the finest "Persian turquoise" came from Iran. Today, the most significant commercial source is the southwestern United States (particularly Arizona and Nevada), known for its "spiderweb" matrix patterns. Other notable sources include China, Egypt, and Afghanistan.
Gemological Properties Turquoise is a hydrous phosphate of copper and aluminum with the chemical formula CuAl₆(PO₄)₄(OH)₈·4H₂O. Its color ranges from sky blue to bluish-green and green, directly correlated with the amount of copper (blue) and iron (green) present. It is relatively soft and porous, with a Mohs hardness of 5 to 6. This porosity means it is susceptible to damage from chemicals, heat, and even prolonged exposure to skin oils and lotions, which can cause discoloration.
Tanzanite: The Modern Marvel
A relative newcomer to the world of gemstones, Tanzanite was only discovered in the 20th century and quickly rose to prominence due to its singular beauty and limited geographic origin.
History and Lore Tanzanite was discovered in 1967 near the Merelani Hills of northern Tanzania by a Tanzanian prospector named Ali Juuyawatu. The gemstone was brought to the attention of the American jewelry company Tiffany & Co., which recognized its potential and launched a major marketing campaign in 1968, naming it after its country of origin. Due to its limited source, Tiffany & Co. marketed it as "a generation stone," available only to our generation. In 2002, the American Gem Trade Association (AGTA) officially added tanzanite as a birthstone for December.
Geological Formation and Sources Tanzanite is the blue-to-violet variety of the mineral zoisite. It is found in only one location worldwide: a small, four-square-kilometer mining area in the Merelani Hills of Tanzania. Its formation is linked to the metamorphism of the rocks in the East African Rift, a unique geological event that is unlikely to be repeated. This extreme rarity is a key factor in its value.
Gemological Properties Tanzanite is known for its strong trichroism, displaying three different colors when viewed from different crystal directions: blue, violet, and reddish-violet. Its Mohs hardness is 6 to 7, making it suitable for jewelry but requiring some care to avoid scratches. The vast majority of tanzanite on the market has been heat-treated to a stable blue or violet-blue color; this treatment is permanent and is generally considered essential to bring out the stone's desirable hues.
Blue Topaz: The Abundant Beauty
While topaz occurs in a wide spectrum of colors, the brilliant blue variety has become a staple of the modern jewelry market, particularly as a December birthstone.
History and Lore The name "topaz" is thought to derive from the Sanskrit word "tapas," meaning "fire." Historically, confusion often existed between yellow topaz and the mineral citrine. Blue topaz, in its natural form, is exceptionally rare. The vast majority of blue topaz seen in jewelry today is produced by irradiating and heat-treating colorless or pale topaz, a process that is stable and safe.
Geological Formation and Sources Topaz is a silicate mineral of aluminum and fluorine. Natural colorless topaz is abundant and serves as the raw material for creating blue topaz. Major sources of topaz include Brazil, Sri Lanka, Nigeria, and the United States (Texas and California). The treatment process to create blue topaz involves exposing the stone to high-energy radiation, which alters its crystal lattice to produce blue coloration, followed by controlled heating to stabilize the color.
Gemological Properties Blue topaz is a durable gemstone with a Mohs hardness of 8, making it highly resistant to scratching and ideal for everyday wear in rings and bracelets. It has a vitreous luster and good clarity. The most popular shades of blue topaz are "Swiss Blue" (a bright, medium blue) and "London Blue" (a deep, saturated blue). Its affordability and durability have made it a popular choice for large, statement jewelry pieces.
Blue Zircon: The Diamond Alternative
Often confused with the synthetic cubic zirconia, natural zircon is one of the oldest minerals on Earth and a traditional December birthstone with a brilliant sparkle.
History and Lore Zircon has been used as a gemstone for centuries. During the Middle Ages, it was believed to promote sleep, ward off evil spirits, and bring prosperity and honor. Its popularity as a diamond simulant surged in the Victorian era. The confusion with cubic zirconia (CZ), a synthetic material developed in the 1970s, has unfortunately diminished the public's awareness of natural zircon's value.
Geological Formation and Sources Zircon is a zirconium silicate (ZrSiO₄) and is a primary mineral, meaning it is found in igneous and metamorphic rocks. It is a common component of many sands and is used by geologists for radiometric dating due to its durability and resistance to chemical change. Major sources of gem-quality zircon include Cambodia, Sri Lanka, Thailand, and Australia.
Gemological Properties Zircon possesses a very high refractive index, giving it a brilliance and "fire" that can rival that of a diamond. However, it is softer than diamond, with a Mohs hardness of 6.5 to 7.5, and has perfect cleavage in two directions, making it more susceptible to chipping if struck with force. Most blue zircon is heat-treated from brownish zircon to achieve its desirable blue hues. This treatment is stable, but prolonged exposure to sunlight can sometimes cause the blue color to fade over time.
February's Royal Purple: Amethyst
Amethyst, the sole birthstone for February, is a variety of quartz celebrated for its captivating violet shades, which have symbolized royalty, spirituality, and sobriety for millennia.
History and Lore The name "amethyst" comes from the Greek word "amethystos," meaning "not intoxicated." Ancient Greeks and Romans believed the stone could prevent drunkenness and wore it as an amulet or carved drinking vessels from it. This association with clarity and control has persisted through the ages. Amethyst has been a fixture in religious jewelry, particularly for Christian bishops and Catholic clergy, symbolizing piety and humility. It is also the traditional stone for the 6th and 17th wedding anniversaries.
Geological Formation and Sources Amethyst is a variety of crystalline quartz, colored purple by trace amounts of iron and other metal elements within its crystal structure, with the color being intensified by natural irradiation. It is found in geodes and hollow cavities of volcanic rocks. Significant sources include Brazil (the largest producer), Uruguay, Zambia, and Namibia. The finest amethyst comes from Siberia, known for its deep, rich purple color with red and blue flashes, though this source is less productive today.
Gemological Properties Amethyst is a member of the quartz family, with a chemical composition of SiO₂. It has a Mohs hardness of 7, making it a durable and practical gemstone for all types of jewelry. Its color can be highly sensitive to heat, and prolonged exposure to strong light (especially sunlight) can cause its vibrant purple to fade or turn a pale yellow. This fading is often used intentionally by heat-treating lower-grade amethyst to produce the yellow-brown variety known as citrine, or the green variety known as prasiolite.
Symbolism and Metaphysical Beliefs
Beyond their physical beauty and scientific properties, these birthstones carry a rich weight of symbolism and are central to modern crystal healing practices.
- Turquoise is widely regarded as a master healing stone. It is believed to provide protection, tranquility, and good fortune. In modern metaphysical beliefs, it is said to align all the chakras, stabilize mood swings, and instill inner calm.
- Tanzanite is associated with transformation and spiritual awakening. It is believed to facilitate a higher consciousness, psychic abilities, and the understanding of one's destiny. Its energy is considered uplifting and calming.
- Blue Topaz is linked to clear communication, truth, and forgiveness. It is believed to soothe the mind, relieve stress, and promote feelings of joy and abundance.
- Blue Zircon is thought to bring honor and wisdom to its wearer. It is associated with prosperity and is believed to help in achieving one's goals through enhanced focus and discipline.
- Amethyst is strongly connected to peace, intuition, and spiritual awareness. It is considered a natural tranquilizer that can relieve stress, balance the nervous system, and promote restful sleep. It is also believed to enhance meditation and spiritual consciousness.
Care and Cleaning: Preserving Your Birthstones
Understanding the physical properties of each gemstone is crucial for its long-term care. The differences in hardness, cleavage, and sensitivity dictate the proper methods for cleaning and storage.
Caring for Turquoise Due to its low hardness (5-6) and porosity, turquoise is the most delicate of these stones. * Cleaning: Use only a soft cloth, mild soap, and lukewarm water. Dry immediately with a soft, lint-free cloth. * Avoid: Ultrasonic cleaners, steamers, harsh chemicals (including household cleaners, perfumes, and cosmetics), and prolonged exposure to water, which can cause the stone to become dull or discolored. * Storage: Store separately in a cool, dry place to prevent scratches and chemical reactions.
Caring for Tanzanite * Cleaning: Use warm water, a mild detergent, and a soft brush. Avoid ultrasonic cleaners, as the vibrations can cause existing fractures to worsen. * Avoid: Sudden temperature changes and prolonged exposure to strong sunlight or high heat, which can cause the color to fade. * Storage: Store in a soft cloth or padded jewelry box, away from other, harder stones.
Caring for Blue Topaz and Blue Zircon * Cleaning: Both are safe to clean with warm, soapy water and a soft brush. They can be cleaned with an ultrasonic cleaner, but caution is advised for zircon due to its cleavage. Steam cleaning is generally not recommended for zircon. * Avoid: While topaz is very durable, blue zircon is more brittle and prone to chipping. It should be protected from hard blows. Prolonged exposure to sunlight may cause the blue color of some zircon to fade. * Storage: Store separately to prevent scratching other gems or being scratched.
Caring for Amethyst * Cleaning: Amethyst can be safely cleaned with warm, soapy water and a soft brush. It is generally safe for ultrasonic cleaning, except when it has fractures or inclusions. * Avoid: Prolonged exposure to intense light and heat, which can cause fading. It is best not to wear amethyst in direct sunlight for extended periods. * Storage: Store in a jewelry box or pouch to protect it from scratches and light exposure.
Conclusion
The birthstones of December and February offer a compelling narrative of geological wonder, human history, and cultural expression. December's selection—from the ancient, protective turquoise and the modern, singular tanzanite to the brilliant, accessible blue topaz and the fiery, traditional blue zircon—provides a remarkable spectrum of choice for those born in the final month. February's amethyst, with its timeless royal purple hue, offers a singular connection to themes of clarity, peace, and spirituality. Each of these gems, whether an opaque talisman or a transparent jewel, carries a unique story. For the wearer, they serve not only as beautiful adornments but also as a tangible link to the enduring human fascination with the treasures of the Earth, a personal piece of geological history and cultural lore to be cherished for a lifetime.