For individuals born on December 16, the selection of a birthstone is uniquely enriched by a trio of exceptional gemstones: Tanzanite, Turquoise, and Zircon. Unlike months with a single designated stone, December offers a palette of blue hues that span the spectrum from soft sky tones to deep violet-blues and brilliant clear sparks. These gemstones—Tanzanite, Turquoise, and Zircon—are the official modern birthstones for the month, each carrying a distinct history, geological origin, and set of symbolic meanings. While they differ significantly in physical properties and rarity, they are united by their captivating color and their association with themes of success, protection, and inner strength. This article explores the rich lore, scientific properties, and cultural significance of these three remarkable gemstones, providing a detailed guide for enthusiasts, collectors, and anyone born on this auspicious date.
The inclusion of multiple stones for December is a relatively modern development, designed to offer a wider variety of choices in color, style, and price. Tanzanite, a newcomer to the gemological world, offers a unique violet-blue hue found in only one location on Earth. Turquoise is one of the oldest known gemstones, revered by ancient civilizations for its protective qualities. Zircon, often confused with the synthetic cubic zirconia, is a natural gemstone prized for its exceptional brilliance and fire. Together, they form a compelling collection that reflects both the scientific diversity of the mineral kingdom and the enduring human desire for beauty and meaning in adornment.
The Historical Significance and Lore of December's Gems
The journey of these three gemstones to their status as December birthstones is a story of ancient tradition meeting modern recognition. Each stone possesses a lineage that stretches back through centuries, accumulating layers of cultural belief and symbolic power.
Turquoise: The Ancient Talisman
Turquoise stands as the most historically significant of the three, with a pedigree that spans millennia. It has been mined and cherished since at least 3000 B.C., with its name deriving from the French phrase pierre turquoise, meaning "Turkish stone," a reference to the trade routes through which it reached Europe. Ancient Egyptian artisans carved Turquoise into jewelry and amulets, including the iconic burial mask of Pharaoh Tutankhamun, which was inlaid with the stone. For the Egyptians, Turquoise was a symbol of rebirth and the heavens, believed to protect the wearer from harm. Similarly, in Persian and Native American cultures, Turquoise was regarded as a sacred stone, a powerful protector against evil spirits and a conduit for good fortune. Its sky-blue color was associated with the heavens and was thought to bring rain and prosperity. This deep-rooted history as a protective talisman is a cornerstone of its enduring appeal and its designation as a primary December stone.
Tanzanite: The Gem of a Generation
In stark contrast to Turquoise's ancient origins, Tanzanite is a remarkably modern discovery. Found in the mid-1960s near Mount Kilimanjaro in Tanzania, this blue-to-violet variety of zoisite quickly captured the attention of the global jewelry market. Its discovery is attributed to a stroke of luck, when a series of bush fires on the Merelani hills uncovered a deposit of the gemstone, making it easier for local prospectors to spot. The stone’s intense color and relative rarity led to its rapid promotion as a significant new gem. Its status as a birthstone was solidified in 2002 when the American Gem Trade Association (AGTA) added it to the official list of birthstones for December, recognizing its popularity and unique beauty. Although it lacks the millennia-long history of Turquoise, Tanzanite has been imbued with contemporary metaphysical beliefs, focusing on themes of transformation and spiritual awakening.
Zircon: The Stone of Clarity and Wisdom
Zircon is one of the oldest minerals on Earth, with crystals dated to over 4 billion years old, yet its history as a gemstone is often obscured by confusion with the much more recent synthetic material, cubic zirconia. For centuries, however, natural Zircon was a highly prized gemstone. In the Middle Ages, it was believed to promote sleep, ward off evil spirits, and bring prosperity and honor to its wearer. It was also used as a protective travel amulet. Historically, the gem was known for its brilliance, with some sources referring to it as "Jacinth." Zircon’s inclusion as an official December birthstone alongside Turquoise and Tanzanite provides a classic, sparkling blue option that connects the modern wearer to a legacy of ancient belief in the stone’s power to bestow wisdom and clarity.
The official recognition of these three stones—Turquoise, Tanzanite, and Zircon—as December’s birthstones is a modern standardization. Sources indicate that this multiplicity is intentional, designed to offer those born in December a variety of colors and styles, ensuring that every individual can find a stone that resonates with their personal taste while still adhering to traditional birthstone lists.
Geological Formation and Mining Locations
The origins of these gemstones are as diverse as their histories. Each forms under unique geological conditions and is sourced from specific, often geographically limited, locations on the globe.
Tanzanite: A Singular Origin
Tanzanite’s geological story is one of extreme rarity. It is a variety of the mineral zoisite and owes its signature blue-violet color to the presence of vanadium and other trace elements. What makes Tanzanite exceptionally rare is that it is found in only one location worldwide: the Merelani Hills of Northern Tanzania, a small mining area near the majestic Mount Kilimanjaro. The gemstone is formed through a complex geological process involving intense heat and pressure acting on the parent rock, a phenomenon believed to have occurred during the formation of the East African Rift Valley. This singular source means that the entire global supply of Tanzanite originates from an area just a few kilometers long, making its availability finite and contributing significantly to its value and allure.
Turquoise: A Hydrous Copper Mineral
Turquoise is a phosphate mineral that forms when water containing copper and aluminum seeps through rocks rich in these elements. Its color, which ranges from soft sky blue to greenish hues, is directly dependent on the amount of copper (for blue) and iron (for green) present during its formation. Unlike Tanzanite, Turquoise is found in arid regions around the world. Historically significant sources include Iran (Persia), Egypt, and the Southwestern United States (Arizona, New Mexico, Nevada). The United States is a major producer, with American Turquoise often occurring in veins or nuggets within a host rock, such as quartz or limonite, creating distinctive matrix patterns that are prized by connoisseurs.
Zircon: A Primary Zirconium Silicate
Zircon (ZrSiO₄) is a zirconium silicate mineral that forms in igneous and metamorphic rocks. It is a primary crystal, meaning it crystallizes directly from molten magma. Its exceptional hardness and durability allow it to survive weathering, becoming a component of sand and sediment. For gemstone purposes, the most prized blue Zircon is often heat-treated to achieve its vibrant color, as most natural zircon is brownish. Major sources for gem-quality Zircon include Cambodia, Sri Lanka, Thailand, and Australia. The stone’s high refractive index gives it a brilliance that can rival diamond, making it a popular and affordable alternative for those seeking a sparkling blue gem.
Gemological Properties: A Scientific Comparison
Understanding the physical and chemical properties of these gemstones is crucial for appreciating their differences in durability, appearance, and care requirements. The following table provides a direct comparison based on the information available in the provided sources.
| Property | Tanzanite | Turquoise | Zircon |
|---|---|---|---|
| Mineral Species | Zoisite | Phosphate Mineral | Zircon |
| Chemical Formula | Ca₂(AlOH)SiO₄ | Hydrated copper/aluminum phosphate | ZrSiO₄ |
| Hardness (Mohs Scale) | 6.5 - 7 | 5 - 6 | 6.5 - 7.5 |
| Crystal System | Orthorhombic | Triclinic | Tetragonal |
| Refractive Index | 1.690 - 1.700 | 1.610 - 1.650 | 1.920 - 2.010 |
| Color Range | Deep blue to violet | Sky blue to greenish blue | Blue, brown, green, yellow, red |
Hardness and Durability: Hardness is a critical factor in determining a gemstone's suitability for jewelry, especially for rings worn daily. On the Mohs scale, Turquoise is the softest of the three, ranging from 5 to 6. This makes it susceptible to scratching and damage from chemicals, lotions, and even skin oils, which can cause discoloration over time. Tanzanite and Zircon are harder, with Mohs ratings of 6.5-7 and 6.5-7.5 respectively. This makes them more resilient to everyday wear, though they are still not as hard as top-tier gems like sapphire or diamond and should be handled with care.
Color and Optical Properties: The color is the most defining characteristic of each stone. Tanzanite’s appeal lies in its trichroism—the ability to display three different colors (blue, violet, and reddish-gray) when viewed from different crystal directions. This dynamic color play gives it a unique, mesmerizing depth. Turquoise is typically opaque with a waxy to vitreous luster, and its color is often consistent and uniform, though matrix-included varieties offer complex patterns. Zircon’s primary draw is its exceptional brilliance and fire, a result of its very high refractive index. Blue Zircon, in particular, is known for its bright, sparkling appearance that can mimic the look of a diamond or sapphire.
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, these gemstones are steeped in symbolic meaning and metaphysical beliefs, which continue to be a major driver of their popularity.
Tanzanite is widely associated with transformation and spiritual enlightenment. Believers claim it can open the "third eye" and enhance intuition, guiding the wearer on a path of self-discovery. It is also considered a stone of communication, thought to aid in articulating thoughts and emotions clearly. Furthermore, it is believed to be a protective stone that dispels negative energies and promotes healing.
Turquoise is perhaps the ultimate protective talisman. Across cultures, it has been used to ward off evil and bring good fortune. It is also associated with healing and balance, believed to stabilize mood cycles and promote inner calm. Its connection to the sky and water makes it a symbol of peace and tranquility.
Zircon is linked to clarity, wisdom, and balance. It is thought to help organize one’s thoughts and enhance self-confidence. Historically, it was believed to promote honor and prosperity. For those born on December 16, Zircon is said to bring a sense of stability and mental clarity, helping them navigate life’s challenges with wisdom.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of these gemstones, with each requiring a slightly different approach due to their unique properties.
Tanzanite and Zircon: Due to their higher hardness (6.5-7.5), these stones are more durable. They can be safely cleaned using warm water, a mild soap, and a soft brush. However, they can be susceptible to fracture, so avoid ultrasonic cleaners and steam cleaning, as sudden temperature changes can cause damage. Zircon, in particular, should be kept away from extreme heat, which can alter its color.
Turquoise: As the softest and most porous of the three, Turquoise requires the most delicate care. It should never be exposed to heat, chemicals, or even prolonged direct sunlight, which can cause it to become brittle or fade. Cleaning should be done gently with a soft, dry cloth. Avoid soaking Turquoise in water or using any commercial jewelry cleaners, as these can damage the stone’s surface and color.
Conclusion
The birthstones for December 16—Tanzanite, Turquoise, and Zircon—offer a compelling trio of options that cater to a wide range of preferences. Turquoise provides a connection to ancient history and a powerful symbol of protection with its classic sky-blue hue. Tanzanite presents a modern, sophisticated choice, prized for its exclusive origin and mesmerizing violet-blue color that speaks of transformation and spiritual depth. Zircon offers brilliant sparkle and a link to ancient wisdom, combining durability with a timeless appeal. While they differ in hardness, origin, and lore, they are united by their beautiful blue tones and their role as meaningful talismans for those born in December. The choice between them allows for a personal expression of style, whether one is drawn to the historic legacy of Turquoise, the singular rarity of Tanzanite, or the dazzling fire of Zircon.