For those born in the final month of the year, the birthstone selection is not a single gem but a vibrant trio of blue stones: Turquoise, Tanzanite, and Zircon. Each possesses a distinct geological origin, historical narrative, and set of gemological properties, yet all share the cool, captivating color palette associated with winter. While Turquoise stands as the traditional and most ancient representative, Tanzanite and Zircon have secured their places as modern and brilliant alternatives, respectively. This article provides a comprehensive exploration of these three official December birthstones, detailing their formation, sources, physical characteristics, and the lore that has made them enduring symbols of success, wisdom, and protection.
The journey into the world of December's gems reveals a spectrum of blue, from the opaque, sky-like tones of Turquoise to the violet-blue pleochroism of Tanzanite and the fiery brilliance of Blue Zircon. Understanding the unique attributes of each stone allows enthusiasts and collectors to appreciate not just their beauty, but the remarkable geological processes and human history embedded within each specimen.
Turquoise: The Ancient Traditional Birthstone
Turquoise is unequivocally the oldest and most traditional of the December birthstones. Valued by civilizations spanning the globe for millennia, this semi-translucent to opaque gem is defined by its distinctive blue-to-green coloration and the presence of matrix.
History and Lore
The historical footprint of Turquoise is immense. Evidence of its use dates back over 3,000 years in China, where artisans carved it into decorative objects. In ancient Egypt, pharaohs and powerful rulers adorned themselves with the stone, believing it possessed protective and beneficial powers. The name "Turquoise" itself is derived from the French phrase pierre turquoise, meaning "stone of Turkey." This nomenclature arose because the gem was introduced to Europe through Turkish bazaars, having traveled along trade routes from its original mining locations in Persia (modern-day Iran).
The belief in Turquoise's protective qualities persisted well into the Middle Ages. It was widely held that the stone could safeguard the wearer from falling, particularly from horses, and that it would shatter at the approach of disaster as a warning. Hindu mystics associated the gem with wealth, maintaining that gazing upon a turquoise after seeing the new moon would ensure fantastic fortune. Native American cultures, specifically the Apache, also held the stone in high regard, believing it could be found by following a rainbow to its end.
Geological Formation and Sources
Turquoise forms through a unique geological process involving groundwater. Water containing copper seeps into the bedrock, and over time, reactions with other minerals create the opaque stone. The resulting color spectrum, ranging from sky blue to green, is dictated by the specific mineral content; copper produces blue, while iron contributes to green hues. The dark veins and shapes visible within the stone are remnants of the surrounding rock, known as matrix.
Among the various sources of Turquoise, specific varieties are highly prized. Persian turquoise, historically sourced from ancient mines in Iran, is celebrated for its vivid, evenly saturated sky-blue color and a characteristically minimal to nonexistent matrix. Another renowned variety is Sleeping Beauty Turquoise, named for the mountain in Arizona from which it was mined before the mine's closure. This variety is treasured for its pure, robin's-egg blue color and smooth, uniform appearance, lacking the matrix often seen in other specimens.
Gemological Properties
Turquoise is an opaque phosphate mineral that contains copper and aluminum. Its hardness on the Mohs scale typically ranges from 5 to 6, making it relatively durable for jewelry but susceptible to scratching if not handled with care. Its opacity means that light does not pass through it, contributing to its rich, solid color.
Tanzanite: The Modern Sensation
In stark contrast to the ancient history of Turquoise, Tanzanite is the newest addition to the December birthstone family, discovered less than 60 years ago. Its rapid ascent to prominence is a testament to its unique beauty and singular origin.
History and Origins
Tanzanite's story is remarkably modern. It was discovered in a small, restricted area near Mount Kilimanjaro in Tanzania. Recognizing its potential, Tiffany & Company launched a major promotional campaign in 1968 to introduce the gem to the world, highlighting its exclusive geographic origin. This marketing effort was highly successful, and Tanzanite quickly became a sought-after gem. Due to its rarity and limited source, it is also recognized as the 24th-anniversary gemstone.
Gemological Properties
The most captivating characteristic of Tanzanite is its pleochroism. When viewed from different angles, the gem displays different colors, specifically a striking blue-violet hue. Most gem-quality tanzanite undergoes a heat treatment to enhance and stabilize this vivid color.
With a hardness of 6 to 7 on the Mohs scale, Tanzanite is moderately durable. However, it is sensitive to sudden temperature changes and has cleavage planes, meaning it can break if struck with sufficient force.
Care and Cleaning
Due to its sensitivity, Tanzanite requires specific care. It should be cleaned only with warm, soapy water. Ultrasonic and steam cleaners are strictly avoided, as they can cause damage due to the stone's cleavage and sensitivity to heat.
Zircon: The Brilliant and Ancient Mineral
Zircon is the third official December birthstone, often overshadowed by the other two but possessing a brilliance and history all its own. It is important to distinguish this natural gemstone from the synthetic cubic zirconia often used as a diamond simulant.
History and Significance
Zircon is the oldest known mineral on Earth, with samples found in Australia dating back an astonishing 4.4 billion years. The origin of its name is debated, possibly deriving from the Arabic zarkun ("vermillion") or the Persian zargun ("gold-colored"). While Zircon occurs in a wide spectrum of colors including yellow, green, brown, red, and clear, the blue variety is the one linked to December. In the Middle Ages, Zircon was believed to promote wisdom, honor, and restful sleep.
Gemological Properties
Zircon is a silicate mineral renowned for its exceptional brilliance and high refractive index, which is higher than that of a diamond. This optical property gives cut Zircon a dazzling fire and sparkle. The blue variety, which is the birthstone representative, is often achieved through heat treatment of brownish zircon crystals.
Care and Cleaning
Zircon has a hardness of 7.5 on the Mohs scale, making it a relatively hard and durable gem. However, it can be brittle due to its crystal structure. It is susceptible to chipping if knocked against a hard surface. Care should be taken to protect it from sharp blows. Like the other December stones, it is best cleaned with warm, soapy water and a soft brush, avoiding harsh chemicals and ultrasonic cleaners.
The Color of December: Blue Topaz as an Alternative
While Turquoise, Tanzanite, and Zircon are the official birthstones, Blue Topaz is frequently cited as a popular alternative or modern choice for December. Its widespread availability and range of blue shades have made it a favorite in contemporary jewelry.
Blue Topaz is a silicate mineral composed of aluminum and fluorine. It possesses a glass-like luster but has deep cleavage, making it somewhat delicate despite its hardness of 8 on the Mohs scale. Most of the blue topaz available on the market today is produced by irradiating naturally colorless topaz. The resulting color varieties are distinct: * London Blue Topaz: A deep, inky blue. * Swiss Blue Topaz: A vibrant, medium-light blue. * Sky Blue Topaz: A light aqua color.
The name "topaz" is believed to derive from the Sanskrit word for "fire." Its similarity in color to aquamarine sometimes leads to confusion, but its treatment process and geological origin are distinctly different.
Symbolism and Metaphysical Beliefs
Across cultures and centuries, the blue stones of December have been imbued with powerful symbolism. Turquoise has long been associated with success, happiness, and prosperity. Its protective lore is extensive, ranging from preventing falls to warning of impending danger. Tanzanite, as a modern gem, is often linked to transformation and new beginnings, perhaps reflecting its sudden appearance on the gemological scene. Zircon, in its historical context, was a symbol of wisdom and honor, with the added benefit of promoting peaceful sleep. The common thread among them is the calming and spiritual nature of the color blue, representing wisdom, tranquility, and good fortune.
Conclusion
The December birthstones offer a remarkable diversity within a shared color palette. Turquoise provides a connection to the ancient world with its opaque, sky-blue beauty and rich history of protection and prosperity. Tanzanite presents a modern marvel, a rare gem from a single source on Earth, captivating with its violet-blue pleochroism. Zircon, the ancient mineral, offers unparalleled brilliance and a connection to the very formation of our planet. Together, they provide a rich selection for those born in December, each stone telling a unique story of geological formation, human history, and enduring symbolism.