For those born in the final month of the year, the birthstone selection is notably diverse and visually stunning. Unlike months with a single traditional gem, December offers a palette of cool, serene blues and vibrant violets, reflecting the wintry skies and icy landscapes associated with its place on the calendar. The primary traditional birthstone is Turquoise, a semi-translucent to opaque gem celebrated for its unique sky-blue to greenish hues. In modern times, this has been joined by the vivid violet-blue of Tanzanite and the brilliant, multifaceted sparkle of Zircon. Blue Topaz is also frequently cited as a popular modern alternative, offering a more affordable and readily available option in a spectrum of blue shades. Together, these stones provide a wide array of choices for jewelry buyers and enthusiasts, each possessing a unique history, distinct gemological properties, and a rich tapestry of cultural symbolism.
This guide will explore the four principal gemstones associated with December birthdays: Turquoise, Tanzanite, Zircon, and Blue Topaz. We will delve into the geological origins and sources of each stone, detail their scientific properties, uncover the historical lore that has cemented their status as birthstones, and provide practical advice for their care and maintenance. By examining the distinct characteristics of each gem, we can appreciate why these particular stones have been chosen to represent the last month of the year.
History and Lore
The tradition of associating specific gemstones with birth months has evolved over millennia, with roots in ancient civilizations. The modern list of birthstones is largely derived from a tradition established in the first century by Flavius Josephus, a historian, and later formalized by the National Association of Jewelers in 1912. For December, the historical narrative is dominated by Turquoise, though the other stones have accumulated their own fascinating histories.
Turquoise: The Ancient Talisman
Turquoise is arguably the oldest and most historically significant of the December birthstones. It has been cherished for thousands of years, with evidence of its use dating back to ancient Egypt, where pharaohs and other rulers adorned themselves with the gem. Chinese artisans were carving Turquoise more than 3,000 years ago, demonstrating its early global appeal. The name "Turquoise" itself is derived from the French phrase pierre turquoise, meaning "stone of Turkey." This name originated because the gem was brought to Europe from Turkish bazaars, where it was traded by merchants traveling from its primary source in Persia (modern-day Iran).
Throughout history, Turquoise has been imbued with powerful protective and beneficial properties. It was widely believed to guarantee health and good fortune to its wearer. From the 13th century onward, a prominent European belief held that Turquoise could protect a person from falling, particularly from a horse, and that the stone would shatter into several pieces as a warning of an impending disaster. This idea of the stone acting as a physical barometer for danger is a recurring theme in its lore. Hindu mystics believed that seeing a Turquoise after first beholding the new moon would ensure fantastic wealth. The stone also played a vital role in the lives of Native American cultures. The Apache, for instance, believed that Turquoise could be found by following a rainbow to its end, and it was used extensively in their spiritual and decorative arts. Across many cultures, Turquoise is considered a sacred stone, symbolizing friendship, protection, and good fortune.
Tanzanite: The Modern Marvel
In stark contrast to the ancient lineage of Turquoise, Tanzanite is a relative newcomer to the world of gemstones. Its history is remarkably short and dramatic. Tanzanite was officially discovered and recognized as a distinct gemstone species in 1967 in the Merelani Hills of Northern Tanzania, near the base of Mount Kilimanjaro. The gemologist who identified it, Manuel de Souza, initially thought he had found an olivine deposit, but its unique blue-violet color quickly revealed it as something entirely new. It was eventually identified as a variety of the mineral zoisite and was named "Tanzanite" by Tiffany & Co., which introduced the stone to the global market in 1968 and promoted it heavily due to its alluring color and single-source origin. Its rapid rise to prominence led to its inclusion in the modern list of birthstones for December, representing a significant update to the traditional list.
Zircon: The Gem of Royalty
Zircon is another of the traditional birthstones for December, with a history that rivals Turquoise for antiquity. The name Zircon may derive from the Persian word zargun, meaning "gold-colored," though the gem is most prized for its brilliant blue varieties. For centuries, Zircon has been associated with royalty and was believed to promote honor and prosperity in the home of its wearer. It was a popular decorative stone in the Middle Ages, often used to ward off evil spirits and ensure a restful night's sleep. While it is available in a rainbow of colors, the blue Zircon of December has long been celebrated for its exceptional brilliance and fire, which can rival that of a diamond.
Blue Topaz: The Popular Alternative
Blue Topaz has emerged as a popular modern birthstone for December, particularly in the United States. While the name "Topaz" comes from the Greek Topazios, the ancient name for an island in the Red Sea, it is important to note that the stones mined on that island were later discovered to be Peridot, not Topaz. The name, however, stuck. Natural blue Topaz is rare; the vibrant sky-blue to deep aqua shades seen in jewelry today are almost always the result of irradiation and heat treatment of a colorless or pale Topaz. This treatment process makes the beautiful blue color accessible and affordable, contributing to its widespread popularity as a December birthstone alternative.
Geological Formation and Sources
Each of the December birthstones forms under unique geological conditions, which accounts for their distinct appearances and properties. Their sources are also geographically specific, with some being found in only one location in the world.
Turquoise
Turquoise is a secondary mineral that forms when water containing copper and aluminum seeps through porous rock, such as limestone. Over long periods, these minerals precipitate and solidify into the opaque, waxy gemstone. The presence of copper is responsible for the characteristic blue color, while iron and chromium can create greenish hues.
The most historically significant source of fine Turquoise is Iran, which produces a classic "sky blue" stone. However, major commercial sources today include the United States (particularly Arizona and New Mexico), Tibet, and India. The material from these locations varies in color and matrix (the vein-like remnants of the host rock), giving each region's Turquoise a unique character.
Tanzanite
Tanzanite's formation is a geological rarity. It is found in only one place on Earth: a small, four-square-kilometer mining area in the Merelani Hills of Northern Tanzania. The gem is a variety of zoisite that is heated naturally by the region's geothermal activity, transforming its original brownish color into the coveted blue-violet. The process that created Tanzanite is believed to have occurred over 585 million years ago. Due to its extremely limited geographic source, Tanzanite is considered one of the rarest gemstones in the world.
Zircon
Zircon is a mineral belonging to the nesosilicate group and is one of the oldest minerals on Earth, with some zircon crystals dating back billions of years. It is found in a wide variety of geological environments. While it is mined in many countries, including Australia, Sri Lanka, Thailand, and Cambodia, the sources of the highly prized blue Zircon are more specific. Much of the blue Zircon on the market today comes from Cambodia, with other notable sources in Myanmar and Vietnam.
Blue Topaz
Topaz is a silicate mineral that forms in igneous rocks, particularly in cavities within rhyolite lava. It is found in various locations around the world, including Brazil, Sri Lanka, Nigeria, and the United States (Texas and Utah). As mentioned, natural blue Topaz is rare. The vast majority of the vibrant blue Topaz seen in the market is produced by treating colorless Topaz with irradiation and heat. This process is stable and permanent, and the resulting blue color is what has made Topaz a commercially successful and widely available birthstone for December.
Gemological Properties
Understanding the physical and chemical properties of these gemstones is crucial for gemologists, jewelers, and consumers, as these characteristics determine a stone's durability, appearance, and value.
| Gemstone | Mineral Group | Chemical Formula | Mohs Hardness | Crystal System | Typical Treatments |
|---|---|---|---|---|---|
| Turquoise | Phosphate | CuAl₆(PO₄)₄(OH)₈·4H₂O | 5 - 6 | Triclinic | Stabilization, Waxing/Oiling |
| Tanzanite | Zoisite (Sorosilicate) | Ca₂Al₃(SiO₄)₃(OH) | 6 - 7 | Orthorhombic | Heat |
| Zircon | Zirconium Silicate | ZrSiO₄ | 6.5 - 7.5 | Tetragonal | Heat (for blue color) |
| Blue Topaz | Topaz (Fluorine Silicate) | Al₂SiO₄(F,OH)₂ | 8 | Orthorhombic | Irradiation, Heat |
Turquoise
Turquoise is an opaque mineral with a Mohs hardness of 5 to 6, making it relatively soft and porous. It is a hydrous copper aluminum phosphate. Its color ranges from sky blue to greenish-blue, depending on the amount of copper and iron present. Turquoise often contains dark, web-like inclusions known as matrix, which are remnants of the host rock in which it formed. Due to its porosity, Turquoise is often treated with wax or oil to enhance its color and luster and to protect it from damage. Some lower-grade material is also "stabilized" by impregnating it with a resin to increase its hardness and durability.
Tanzanite
Tanzanite is a variety of the mineral zoisite and has a Mohs hardness of 6 to 7, making it moderately durable but susceptible to chipping and abrasion if not handled with care. It has a trichroic nature, meaning it can display three different colors when viewed from different angles: blue, violet, and a reddish-brown or burgundy. Most Tanzanite sold today has been heat-treated to remove the brownish components and enhance the desirable blue-violet hue. This treatment is stable and permanent.
Zircon
Zircon is one of the heaviest natural gemstones, possessing a high refractive index that gives it exceptional brilliance and fire. It has a Mohs hardness of 6.5 to 7.5, making it suitable for most types of jewelry, though it can be brittle due to its tetragonal crystal structure. The blue variety is typically created through heat treatment of brownish zircon, a process that can be repeated if the stone is subjected to high temperatures during jewelry manufacturing.
Blue Topaz
Blue Topaz is a very hard and durable gemstone, with a Mohs hardness of 8. It has a trigonal crystal structure and is a silicate mineral containing fluorine and hydroxyl. Its transparency and high refractive index give it a brilliant sparkle. As noted, the intense blue color of most Topaz on the market is the result of irradiation followed by heat treatment. This process is accepted industry-wide and produces a permanent color.
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, gemstones have long been associated with symbolic meanings and metaphysical powers. These beliefs add a layer of personal significance to the stones, making them meaningful gifts for December birthdays.
- Turquoise: Universally regarded as a stone of protection, calmness, and good fortune. It is believed to be a master healer, promoting well-being and dispelling negative energy. Its association with friendship makes it a popular gift between friends as a symbol of trust and affection.
- Tanzanite: As a relatively new stone, its metaphysical meanings are more modern. It is often associated with transformation, spiritual awakening, and heightened intuition. Its unique trichroic nature is seen as a metaphor for integrating different aspects of oneself. It is also believed to promote a sense of calm and composure.
- Zircon: This stone is linked to honor, wealth, and wisdom. It was historically believed to aid in sleep and ward off evil spirits. Blue Zircon, in particular, is associated with clarity of thought and spiritual grounding.
- Blue Topaz: Known as a stone of love and affection, Blue Topaz is believed to promote truth, forgiveness, and good health. Its serene blue color is associated with tranquility, peace, and clear communication.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of gemstone jewelry. The durability of each December birthstone varies significantly, dictating the appropriate cleaning methods and handling precautions.
- Turquoise: Due to its relative softness and porosity, Turquoise requires gentle care. It should be cleaned with warm, soapy water and a soft cloth. Avoid ultrasonic cleaners, steam cleaners, and harsh chemicals, as these can damage the stone or strip away any protective wax treatments. Store it separately to prevent scratching by harder gems.
- Tanzanite: With a Mohs hardness of 6-7, Tanzanite is moderately durable but can be brittle. It is best suited for earrings or pendants rather than rings, which are more prone to impact. Clean with warm, soapy water and a soft brush. Avoid sudden temperature changes and ultrasonic cleaners.
- Zircon: Although fairly hard, Zircon is brittle and can chip if knocked against a hard surface. It is generally safe to clean with warm, soapy water and a soft brush. However, caution is needed with ultrasonic cleaners, and it is wise to avoid extreme heat, which can alter its color.
- Blue Topaz: As the hardest and most durable of the group (Mohs 8), Blue Topaz is well-suited for all types of jewelry. It can be safely cleaned with warm, soapy water and a soft brush. It is also generally safe in an ultrasonic cleaner, though caution is still advised for pieces with other, more delicate gemstones.
Conclusion
The birthstones of December offer a remarkable range of choices, from the ancient, earthy allure of Turquoise to the modern, celestial brilliance of Tanzanite, the fiery sparkle of Zircon, and the clear, cool blue of Topaz. Each gem tells a unique story, shaped by millions of years of geological processes and thousands of years of human history and belief. Whether chosen for its historical significance, its symbolic meaning, or simply its captivating color, any of these four stones provides a perfect representation for those born in the last month of the year. Their combined legacy of beauty, durability, and lore ensures that they will continue to be cherished for generations to come.