The final month of the year is uniquely represented by three distinct and captivating gemstones: Turquoise, Tanzanite, and Blue Topaz. This trio offers a remarkable spectrum of cool, vivid blues, from the opaque, sky-worn heritage of Turquoise to the velvety, violet-blue depths of Tanzanite and the brilliant, electric sparkle of Blue Topaz. As the official birthstones for December, these gems are celebrated for their ability to reflect the serene and crystalline beauty of winter skies, making them cherished choices for birthdays, anniversaries, and significant life events.
This comprehensive guide delves into the unique characteristics of each of these three December birthstones. It explores their individual identities in terms of gemological properties, styling considerations, and care requirements, providing a detailed overview for enthusiasts, collectors, and anyone seeking to understand the gems that define this winter month.
The Trio of December Gems
The modern designation of three birthstones for December provides a diverse palette for personal expression. Each gem possesses a unique geological origin, visual character, and set of properties that distinguish it from the others.
Turquoise: The Ancient Sky Stone
Turquoise is arguably one of the oldest known gemstones in human history, revered for millennia for its distinctive sky-blue to blue-green color. It is an opaque mineral composed of hydrated phosphate of copper and aluminum. Its color, which can range from greenish-blue to a pure, intense azure, is primarily determined by the amount of copper (providing blue) and iron (introducing green) present during its formation.
The sources of Turquoise are scattered across the globe, with significant deposits found in the arid regions of the Southwestern United States, Iran, Egypt, and Tibet. Each region produces stones with unique characteristics. For instance, Persian Turquoise is often prized for its pure, robin's-egg blue color, while Turquoise from the American Southwest frequently exhibits a matrix—a web-like pattern of the host rock (such as chrysocolla or pyrite) embedded within the stone. This matrix can create stunning visual effects, with spiderweb patterns being particularly valued.
From a gemological perspective, Turquoise has a hardness of 5 to 6 on the Mohs scale, making it relatively durable but susceptible to scratching and chemical damage. Its opacity is a key feature; unlike many other gemstones, Turquoise is valued for its color and matrix rather than its transparency or brilliance. The stone's porous nature means it can be treated to enhance its color and stability, a common practice in the industry to ensure its longevity as a jewelry gem.
Tanzanite: The Blue-Violet Sensation
A relative newcomer to the gemstone world, Tanzanite was first identified in 1967 in the Merelani Hills of Northern Tanzania, making it one of the only major gemstones to be discovered in the 20th century. It is the blue-to-violet variety of the mineral zoisite, and its color is its most defining characteristic. Tanzanite exhibits a unique and dramatic pleochroism, meaning it displays different colors when viewed from different crystal directions—typically blue, violet, and a reddish hue.
The source of Tanzanite's captivating color is trace amounts of vanadium within its chemical structure. Over time, natural Tanzanite can fade if exposed to heat and light, a process that is often reversed through heat treatment, which also intensifies the stone's blue and violet hues. This heat treatment is standard and permanent, and most commercially available Tanzanite has undergone this process.
Tanzanite is found in only one location on Earth—the Merelani Hills near Mount Kilimanjaro in Tanzania. This geographic rarity contributes significantly to its value and allure. The gemstone has a hardness of 6.5 to 7 on the Mohs scale, making it suitable for most types of jewelry, though it requires more care than harder stones like Sapphire or Topaz. Its transparency and velvety luster make it a stunning center stone for rings, pendants, and earrings, particularly when cut in emerald or pear shapes to maximize its color saturation.
Blue Topaz: The Electric Blue Gem
Blue Topaz is a transparent gemstone known for its brilliant, electric blue color and exceptional clarity. As a variety of the mineral topaz, which is composed of aluminum silicate with fluorine and hydroxyl ions, Blue Topaz is prized for its vitreous luster and fiery sparkle. The natural color of topaz is typically colorless or pale yellow; the intense, deep blue shades associated with Blue Topaz are almost always the result of irradiation and heat treatment applied to colorless Topaz crystals.
The gemstone is sourced from various locations worldwide, including Brazil, Nigeria, Sri Lanka, and the United States. Its hardness of 8 on the Mohs scale makes it an exceptionally durable choice for all forms of jewelry, including rings and bracelets that are subject to daily wear. Its high refractive index contributes to its brilliance, allowing it to capture and reflect light with impressive intensity.
Blue Topaz comes in several commercially recognized shades, including the lighter Sky Blue, the more saturated Swiss Blue, and the deep, inky London Blue. This range of blues offers consumers a wide spectrum of choices, from a subtle, summery hue to a dramatic, dark blue reminiscent of a twilight sky.
Styling and Aesthetic Considerations
Each of the December birthstones offers unique styling possibilities, allowing them to be integrated into a wide range of personal aesthetics, from modern and minimalist to rich and eclectic.
Pairing with Precious Metals
The choice of metal can dramatically alter the appearance of a December birthstone. Turquoise, with its opaque, sky-blue to greenish tones, creates a crisp and contemporary look when paired with cool metals like white gold, silver, or platinum. These metals enhance the stone's natural color without competing for attention. In contrast, Yellow Gold can lend a warmer, more vintage or bohemian feel to Turquoise jewelry.
Tanzanite’s complex violet-blue coloration is beautifully complemented by Yellow Gold, which creates a rich contrast that makes the purple depths of the stone appear even more striking. The warmth of the gold plays against the cool tones of the gem, enhancing its regal quality. White gold and platinum settings provide a more modern and sleek frame, allowing the stone's unique color to be the primary focus.
Blue Topaz, with its clear, vibrant blue, shines brilliantly in platinum settings. The bright, white metal amplifies the gem's electric blue sparkle, creating a look of pure, icy elegance. It also pairs exceptionally well with white gold and silver, maintaining a cool, sophisticated palette.
Creative Combinations and Custom Designs
Beyond traditional metal pairings, these gemstones offer a canvas for creativity. Turquoise, in particular, lends itself to unique, custom designs. Its natural, earthy character allows it to be paired with organic materials like dinosaur bone, whiskey barrel wood, or even meteorite inlays, creating one-of-a-kind wedding bands or statement rings. The porous nature of Turquoise also makes it a candidate for creative inlays, such as incorporating sand from a meaningful beach trip directly into the stone or its setting.
Stacking rings is another popular trend for December stones. A simple Turquoise band can be stacked next to a plain gold wedding ring to create visual interest and a pop of color. Tanzanite and Blue Topaz can be set in adjacent rings or as part of a multi-stone band to create a gradient effect within the blue-to-violet spectrum.
For necklaces and pendants, these stones serve as excellent focal points. A solitaire Tanzanite pendant offers a touch of sophisticated luxury, while a bezel-set Turquoise pendant provides a more relaxed, artisanal feel. Layering these necklaces with other pieces or against a backdrop of neutral-toned clothing—such as charcoal grays, cream sweaters, or deep navy—can make the vivid blue hues of all three stones stand out beautifully.
Gemological Properties and Durability
Understanding the physical properties of each stone is crucial for both jewelers and owners, as it directly informs how the gem should be cared for and set.
| Gemstone | Mineral Species | Chemical Composition | Hardness (Mohs Scale) | Key Characteristics |
|---|---|---|---|---|
| Turquoise | Turquoise | Hydrated phosphate of copper and aluminum | 5 - 6 | Opaque, porous, often contains a matrix |
| Tanzanite | Zoisite | Calcium aluminum hydroxyl silicate | 6.5 - 7 | Strong pleochroism (blue, violet, red), often heat-treated |
| Blue Topaz | Topaz | Aluminum silicate with fluorine and hydroxyl | 8 | Transparent, vitreous luster, brilliant blue (treated) |
The hardness of a gemstone, measured on the Mohs scale, is a primary indicator of its resistance to scratching. Blue Topaz, at 8, is significantly harder and more durable than Tanzanite (6.5-7) and especially Turquoise (5-6). This makes Blue Topaz an excellent choice for rings and bracelets that are exposed to potential knocks and abrasions.
Tanzanite requires more careful handling due to its moderate hardness and good cleavage in one direction, meaning it can be split if struck with sufficient force in the right orientation. Turquoise, being the softest of the three, is most susceptible to scratches and should be protected from harder materials.
Care and Cleaning for Longevity
Proper maintenance is essential to preserve the beauty and integrity of December birthstone jewelry for generations. The distinct properties of each stone dictate specific care regimens.
General Best Practices
A universal rule for all fine jewelry is to "put it on last when getting ready and remove it first when you get home." This simple habit protects gems from exposure to cosmetics, hairsprays, and perfumes, which can leave a film or cause damage over time. It is also wise to remove jewelry before engaging in activities like gardening, weight training, or washing dishes to avoid physical impact and contact with harsh chemicals.
Proper storage is equally important. To prevent scratches, pieces should be stored separately. Individual soft pouches or compartments in a jewelry box are ideal. Never allow a soft stone like Turquoise to rub against harder stones like Sapphire or Diamond.
Stone-Specific Cleaning Instructions
Turquoise: Due to its porosity, Turquoise is sensitive to chemicals and even prolonged exposure to skin oils and lotions. It should be cleaned gently using only a soft, dry cloth. Avoid ultrasonic cleaners, steamers, and chemical jewelry cleaners entirely. If necessary, a slightly damp cloth with mild, pH-neutral soap can be used, but the stone must be dried immediately and completely.
Tanzanite: This gem can be cleaned with warm water, a mild soap, and a soft brush. As with Turquoise, it should be kept away from ultrasonic cleaners and harsh chemicals. Its cleavage property makes it vulnerable to sudden temperature changes, so avoid exposing it to extreme shifts.
Blue Topaz: Thanks to its superior hardness and lack of cleavage, Blue Topaz is the easiest of the three to care for. It can be safely cleaned using warm soapy water and a soft brush. It is also generally safe in an ultrasonic cleaner, though it is always best to check with a professional jeweler if the stone is set in a delicate or antique piece. However, it is important to note that Blue Topaz can be sensitive to prolonged high heat, which might alter its color.
Conclusion
The December birthstones—Turquoise, Tanzanite, and Blue Topaz—offer a compelling trio of choices that cater to a wide array of tastes and styles. From the ancient, opaque charm of Turquoise to the modern, velvety allure of Tanzanite and the brilliant, electric fire of Blue Topaz, each stone carries its own story, properties, and aesthetic. Their shared blue color palette connects them to the cool clarity of winter, while their individual characteristics provide a rich diversity for jewelry design. By understanding their unique origins, properties, and care requirements, one can ensure that these beautiful gems will not only adorn but also endure as cherished pieces for a lifetime and beyond.