December Birthstones – Turquoise, Tanzanite & Zircon

December’s birthstones represent a fascinating journey through time, chemistry, and human discovery. From the ancient wisdom of turquoise to the modern marvel of tanzanite, and the timeless brilliance of zircon, these three gems offer a remarkable range of colors, properties, and stories that make them unique in the world of precious stones. Each has earned its place as a December birthstone through distinct characteristics that appeal to different aspects of beauty and wearing preferences.

What are December’s Birthstones?

December joins June and October as one of the few months blessed with three official birthstones. This trio represents different eras of gemological history and various types of gem formation, offering December-born individuals an exceptionally diverse choice of birthstones. Each stone carries its own significance in different cultures and time periods, providing options that suit various styles, budgets, and preferences.

• Turquoise represents one of humanity’s earliest known gemstones, with a documented history spanning over 7,000 years and significant cultural importance across multiple civilizations.
• Tanzanite emerged as a modern discovery in 1967, becoming one of the most significant gemological finds of the 20th century and rapidly gaining popularity in contemporary jewelry.
• Zircon, despite being one of Earth’s oldest minerals, with crystals dating back 4.4 billion years, remains somewhat overlooked yet offers exceptional brilliance and a rainbow of colors.

These three stones complement each other perfectly, offering options from opaque to transparent, affordable to rare, and modern to ancient. Their diversity makes December one of the most versatile months for birthstone jewelry.

Turquoise

Turquoise holds a unique position among gemstones as one of humanity’s earliest known decorative materials. This opaque blue-to-green stone has adorned royalty, protected warriors, and connected cultures across continents for over seven millennia. Its enduring popularity speaks to both its natural beauty and its rich cultural significance.

What is Turquoise?

Turquoise forms through a complex geological process where water rich in copper and aluminum seeps through rock over millions of years. This seemingly simple composition creates one of the most culturally significant gems in human history, with characteristics that make each piece uniquely identifiable to its source mine.

• Turquoise’s chemical composition (CuAl₆(PO₄)₄(OH)₈·4H₂O) reveals its close connection to water and copper deposits. The interaction of copper with different minerals during formation creates its signature blue-to-green color range, while iron content can shift colors toward green and brown hues.
• The stone typically forms in arid regions where mineral-rich groundwater can interact with specific rock types. This explains its presence in major mining areas like the American Southwest, Iran (Persia), Tibet, and Egypt’s Sinai Peninsula.
• Matrix patterns in turquoise form when the host rock becomes part of the gem material. These distinct patterns, ranging from spider-web to mottled designs, help experts identify specific mine sources and can significantly affect both value and appeal.
• Hardness ranges from 5 to 6 on the Mohs scale, with porosity playing a crucial role in both the stone’s durability and its ability to accept stabilizing treatments. Natural, untreated specimens with high hardness are increasingly rare and valuable.

Understanding turquoise’s formation and physical properties helps explain both its widespread historical use and the modern challenges in sourcing fine specimens. The stone’s porous nature and relatively soft hardness have led to the development of various treatment methods, making knowledge of these factors crucial for both buyers and collectors.

History and Origin

Turquoise represents one of humanity’s most ancient connections to decorative stones, with a documented history stretching back to the earliest civilizations. Its use spans continents and cultures, each adding their own significant chapter to the stone’s rich story and contributing to its enduring value in both jewelry and cultural heritage.

• Ancient Middle Eastern cultures pioneered turquoise use, with Egyptian mines in the Sinai Peninsula dating back to 4000 BCE. The stone adorned famous artifacts including Tutankhamun’s burial mask and royal jewelry throughout numerous dynasties. Persian turquoise, particularly from the Nishapur mines, set the standard for quality that continues to influence the market today.
• Native American civilizations developed their own deep connection to turquoise, using it in religious ceremonies and creating distinctive jewelry styles. The stone was considered a bridge between earth and sky, worn for protection and spiritual power. Southwest mines produced unique varieties with characteristic matrix patterns that are highly valued in modern collecting.
• Chinese artisans carved turquoise for over 3,000 years, often incorporating it into intricate designs alongside jade. Tibetan culture particularly valued the stone, combining it with coral in traditional jewelry and religious objects. This Asian appreciation for turquoise contributed unique aesthetic preferences to the global market.
• Modern American turquoise production peaked in the 20th century, with famous mines like Sleeping Beauty, Bisbee, and Lander Blue creating distinctive varieties sought by collectors. Each mine produced stone with characteristic colors and matrix patterns, allowing experts to identify origins visually.

The historical significance of turquoise has shaped both its value and its role in modern jewelry. Understanding these cultural connections helps explain why certain varieties command premium prices and why traditional cutting and setting styles continue to influence contemporary designs.

Colors and Varieties

The world of turquoise encompasses a remarkable range of colors, patterns, and qualities that make each piece unique. From pure sky blue to rich green, and from clear specimens to complex matrix patterns, turquoise offers variety that few other gemstones can match.

• Persian turquoise traditionally represents the finest quality, characterized by a pure, intense sky-blue color without matrix. This variety sets the standard against which other turquoise is often judged. The color comes from optimal copper content and minimal iron influence during formation.
• American turquoise displays remarkable diversity in both color and matrix patterns. Sleeping Beauty mine produces pure blue stones similar to Persian quality, while Bisbee material shows distinctive chocolate-brown matrix, and Nevada mines yield specimens with complex spider-web patterns highly valued by collectors.
• Color variations occur naturally from blue to green based on the chemical environment during formation. Copper produces blue colors, while increased iron content shifts the color toward green. Some specimens show color zoning or gradual transitions between hues, making each piece unique.
• Matrix patterns, once considered a detriment to value, now play a crucial role in both identification and desirability. These patterns range from fine spider-web designs to bold geometric shapes, with some collectors specifically seeking distinctive matrix configurations from famous mines.

The interplay of color, matrix, and origin has created a complex market where personal preference often outweighs traditional value factors. This diversity allows collectors and jewelry designers to find pieces that perfectly match their artistic vision while potentially increasing in value over time.

Care and Maintenance

Turquoise requires thoughtful care due to its relative softness and porous nature. While it has adorned jewelry for millennia, understanding its vulnerabilities helps preserve its beauty and prevent damage that could diminish both its appearance and value. Modern treatments have improved durability, but proper care remains essential for all turquoise jewelry.

• The porous nature of turquoise makes it particularly susceptible to environmental factors. The stone can absorb oils, chemicals, and cosmetics, potentially changing its color over time. Natural, untreated stones are especially vulnerable, while stabilized turquoise offers better resistance but still requires careful handling.
• Physical care considerations include protecting the stone from impacts, scratches, and extreme temperatures. Turquoise should never be cleaned in ultrasonic or steam cleaners, as these can damage both treated and untreated stones. Avoid exposure to strong light, which can fade the color over time.
• Chemical exposure poses significant risks to turquoise. Common substances like perfume, lotion, and household cleaners can react with the stone’s surface. Even natural skin oils can affect appearance over time. Swimming pools and hot tubs are particularly damaging due to their harsh chemicals.
• Storage requires careful attention to prevent damage from harder materials. Keep turquoise pieces separately in soft cloth bags or lined jewelry boxes. For beaded necklaces, store them flat to prevent strain on the stringing material.

Proper care ensures turquoise jewelry maintains its beauty for generations. Regular cleaning with a soft, damp cloth and immediate attention to any damage helps preserve both the stone’s appearance and its value as a collector’s piece.

Value and Quality Factors

The valuation of turquoise involves multiple factors that differ significantly from those used for transparent gems. Understanding these factors helps buyers make informed decisions and appreciate the unique qualities that contribute to a piece’s worth.

• Color remains the primary value factor, with pure, intense blue traditionally commanding the highest prices. However, market appreciation for green varieties and stones with distinctive matrix patterns has created new value categories. Stability of color, particularly in natural untreated stones, significantly affects long-term value.
• Origin and documentation play crucial roles in valuation, especially for collector-grade stones. Material from famous mines often commands premium prices, with some closed mines like Lander Blue or high-grade Bisbee creating their own premium categories. Persian turquoise continues to represent a quality standard.
• Treatment status significantly impacts value, with natural, untreated stones becoming increasingly rare and valuable. Stabilization, the most common treatment, affects value but improves durability. Understanding different treatment types helps buyers balance aesthetic preferences with practical considerations.
• Craftsmanship in cutting and setting turquoise requires specialized knowledge. The stone’s softness demands careful cutting to preserve material while achieving desired shapes. Traditional Native American techniques like channel inlay work can add significant value to finished pieces.

Modern turquoise valuation balances traditional quality factors with emerging appreciation for unique characteristics. While fine Persian-quality blue remains highly valued, the market increasingly recognizes the artistic merit and cultural significance of distinctive matrix patterns and regional varieties.

Tanzanite

Tanzanite represents a fascinating convergence of geological rarity and modern discovery. This extraordinary gem, found exclusively in a small area near Mount Kilimanjaro, has risen from complete obscurity to become one of the most sought-after colored stones in just over half a century.

What is Tanzanite?

Tanzanite stands as a testament to the continuing possibility of major gemological discoveries in the modern era. This variety of the mineral zoisite transforms from a brownish color to stunning blue-violet through a natural or artificial heating process that alters its crystal structure and electron configuration.

• The stone’s chemical formula is Ca₂Al₃(SiO₄)₃(OH), with trace amounts of vanadium and chromium that create its signature colors through complex interactions with light.
• Tanzanite exhibits remarkable pleochroism, meaning it shows different colors when viewed from different crystallographic directions – typically blue, violet, and burgundy.
• The gem forms in a unique geological environment where high temperatures and pressures, along with the presence of specific trace elements, create the conditions necessary for tanzanite crystallization.
• Most tanzanite undergoes heat treatment at approximately 600°C to enhance its blue color, a permanent process that mimics natural heating within the Earth.

Understanding tanzanite’s unique properties helps explain its special place in the gem world. Its remarkable color change, limited source, and complex crystal structure make it not just beautiful, but also a testament to nature’s ability to create extraordinary gems under precise conditions. These characteristics influence everything from how the stone is cut to how it should be worn and maintained.

History and Origin

The discovery of tanzanite reads like a modern fairy tale in the gem world, marking one of the most significant gemological findings of the 20th century. Its single source location makes it exceptionally rare.

• Ali Juuyawatu, a Maasai tribesman, first discovered blue crystals in the Merelani Hills near Mount Kilimanjaro in 1967, though local legend suggests other Maasai had seen the crystals earlier.
• The stones were initially mistaken for sapphire until they were properly identified as a new variety of zoisite by the world’s leading gem laboratories.
• Tiffany & Co.’s marketing campaign in 1968 launched tanzanite into the spotlight, with their vice president Henry Platt declaring it “the most beautiful blue stone discovered in 2,000 years.”
• The mining area spans only 7 kilometers long by 2 kilometers wide, making tanzanite more than a thousand times rarer than diamonds based on single-source availability.

The story of tanzanite demonstrates how a chance discovery can revolutionize the gem world. With its single source location and growing popularity, tanzanite has established itself as more than just a beautiful gem – it’s become a modern classic that continues to captivate jewelry lovers worldwide. Current estimates suggest the mines may be depleted within several decades, making each tanzanite piece not just beautiful, but increasingly precious.

Colors and Varieties

Tanzanite’s color variations make it one of the most intriguing gems in the jewelry world. The stone’s ability to show different colors based on viewing angle sets it apart from many other precious gems.

• The most valued tanzanite color is a rich blue with a subtle violet overtone, often compared to fine sapphires. This color typically appears most vibrant in larger stones over 5 carats.
• Natural pleochroism in tanzanite creates three distinct colors in different crystal directions: blue, purple-violet, and burgundy red. Skilled cutters orient the stone to display the most attractive blue-violet face-up color.
• Unheated tanzanite often appears brownish or teal, showing different pleochroic colors than heated stones. Some collectors specifically seek these rare, unheated specimens for their unique appearance.
• While most tanzanite appears blue-violet, some stones can show predominantly violet or blue colors. The most valuable specimens display an even, intense color without dark or dull zones.

The complexity of tanzanite’s color behavior makes each stone unique. Cutters must carefully consider the rough crystal’s pleochroism when fashioning the stone, balancing optimal color display with maximum weight retention and brilliance.

Care and Maintenance

Tanzanite’s relative softness and perfect cleavage make proper care essential for maintaining its beauty. Understanding these characteristics helps owners protect their tanzanite jewelry for generations.

• Tanzanite should be protected from impacts and scratches due to its 6.5 hardness on the Mohs scale. Always remove jewelry before exercising, gardening, or doing housework to prevent damage.
• Heat and temperature changes pose significant risks to tanzanite. Never clean the stone with ultrasonic or steam cleaners, and avoid wearing it in saunas, hot tubs, or while sunbathing.
• Daily care should involve gentle cleaning with mild soap and lukewarm water using a soft, lint-free cloth. Harsh chemicals and commercial jewelry cleaners should be avoided.
• Store tanzanite pieces separately from other jewelry to prevent scratches. A soft cloth pouch or padded jewelry box compartment provides ideal protection.
• Regular professional inspection, especially for frequently worn pieces like rings, helps catch potential problems early. Have settings checked annually to ensure stones remain secure.

Proper care ensures tanzanite maintains its stunning color and clarity. While the stone requires attention, its beauty makes the extra care worthwhile, and with proper handling, tanzanite jewelry can become cherished heirlooms.

Zircon

Zircon stands as one of Earth’s oldest minerals, with crystals dating back 4.4 billion years. Despite its ancient origins and exceptional brilliance, this natural gem remains underappreciated in modern jewelry, often confused with cubic zirconia, a synthetic material it shares no relationship with.

What is Zircon?

The microscopic structure of zircon tells an incredible story. Within its crystalline framework lies evidence of Earth’s earliest days, preserved in a stone that can display the fire and brilliance to rival diamond. Its high refractive index creates an exceptional play of light, while its variety of crystal formations results in an array of stunning natural colors, from deep blues to honey browns and fiery reds.

• The gem’s chemical structure (ZrSiO₄) makes it incredibly stable and durable, containing trace elements of uranium and thorium that allow scientists to date ancient rocks. This same composition creates natural colors ranging from golden brown to deep blue, though most commercial zircons undergo heat treatment to enhance their appearance.
• Zircon crystallizes in the tetragonal system, creating exceptional optical properties. Its double refraction and high birefringence produce remarkable fire and brilliance, while its hardness of 6.5-7.5 makes it suitable for all jewelry types when properly set and maintained.
• Natural specimens often show fascinating variations between high and low types – high-type zircons display full crystal development and brilliant optical properties, while low-type stones have begun to break down at an atomic level due to their radioactive content, resulting in lower clarity and duller appearance.
• Despite its durability, zircon can be brittle and requires careful setting in jewelry. The stone’s edges can wear over time, and its double refraction means cutters must orient the stone precisely to maximize its beauty and minimize optical distortions.

Understanding zircon’s internal architecture helps explain its remarkable journey through time. From the early days of Earth’s formation to its eventual discovery in riverbeds and mineral deposits, each zircon crystal carries within it a record of our planet’s history. This combination of scientific significance and natural beauty makes it unique among gemstones, offering both aesthetic appeal and profound geological importance.

History and Origin

The history of zircon reads like a journey through time, from the formation of Earth’s crust to the ornate jewelry of ancient civilizations. This gemstone has witnessed the entire story of our planet, making it not just a beautiful adornment but also a crucial tool for understanding Earth’s history. Its presence in ancient jewelry and religious texts speaks to humanity’s longstanding fascination with its beauty and perceived mystical properties.

• Ancient civilizations valued zircon across multiple cultures – Greeks wrote about its sleep-promoting properties, medieval Europeans used it as a talisman for prosperity and wisdom, and Asian cultures traded fine specimens along the silk routes. These historical uses established zircon’s importance long before its scientific significance was understood.
• Major mining regions each produce distinct varieties: Cambodia’s Ratanakiri province yields the finest blue zircons, Sri Lanka produces a rainbow of colors including prized “Ceylon” varieties, while Myanmar and Vietnam offer exceptional specimens with unique characteristics. Australia’s Jack Hills zircons, though not gem quality, contain Earth’s oldest known material.
• Scientists prize zircon as a geological time capsule, using it to date Earth’s oldest rocks and understand planetary formation. The mineral’s durability and ability to incorporate radioactive elements make it invaluable for studying continental drift and early Earth conditions.
• The modern market particularly values blue zircon, most often created by heating golden or reddish-brown stones. This treatment, developed centuries ago, is stable and accepted in the trade, though untreated natural colors command premium prices among collectors.

The remarkable durability of zircon’s crystal structure has made it an unparalleled record keeper of Earth’s history. While other minerals were destroyed by the planet’s tumultuous geological processes, zircon endured, preserving evidence of our world’s earliest days. This resilience, combined with its beauty and cultural significance, makes zircon a truly extraordinary gemstone that bridges the gap between scientific importance and decorative splendor.

Care and Maintenance

Caring for zircon requires a thoughtful approach that balances its remarkable beauty with its specific vulnerabilities. As one of the oldest minerals on Earth, zircon has survived billions of years in nature, yet in jewelry settings, it needs particular attention to maintain its stunning appearance. Understanding these care requirements ensures that zircon jewelry remains beautiful for generations while preserving its exceptional fire and brilliance.

• The stone’s properties create specific vulnerabilities: its brittle nature means it can chip along cleavage planes, while its relatively soft edges (6.5-7.5 Mohs) can wear down over time. To prevent damage, avoid impacts and store zircon jewelry separately from harder stones that could cause scratches or chips.
• Cleaning methods must be chosen carefully – while warm water with mild soap is safe, ultrasonic cleaners can damage stones, particularly those with existing internal stresses. Steam cleaning should be avoided entirely as sudden temperature changes can cause fractures.
• Environmental factors affect zircon’s appearance and durability: prolonged sunlight exposure can fade some colors, particularly treated blue stones, while household chemicals and cosmetics can damage the stone’s surface over time.
• Professional maintenance should include regular checking of settings and assessment of any wear on facet edges, particularly for rings. Protective settings and proper mounting techniques help prevent damage during daily wear.

The long-term preservation of zircon jewelry depends on understanding both its strengths and limitations. While the stone’s incredible age demonstrates its fundamental durability, its use in jewelry requires specific care considerations. Modern settings and cutting techniques have evolved to protect these gorgeous gems, but owner awareness remains crucial. With proper care, zircon’s remarkable optical properties and rich colors will continue to captivate viewers just as they have for centuries.

Value and Quality Factors

The valuation of zircon involves a complex interplay of multiple characteristics that affect both its market value and desirability. While all gemstones are evaluated based on traditional factors like color, clarity, and cut, zircon presents unique considerations due to its optical properties and variety of treatments. Understanding these factors helps buyers make informed decisions when selecting a stone that best matches their preferences and budget.

• Natural zircons command premium prices, particularly those displaying rich colors without treatment. These untreated stones are increasingly rare in the market, with documented origin adding significant value. The most valuable natural specimens show vivid reds, greens, or pure blues – colors that occur rarely in nature.
• Clarity expectations vary by color and variety, but generally, eye-clean stones are most desirable. High-type zircons should display exceptional transparency and brilliance, while low-type stones may show haziness that affects their value. Inclusions that compromise durability significantly reduce value.
• Size and cut quality are particularly crucial for zircon due to its exceptional optical properties. Larger stones typically command exponentially higher prices per carat, especially in fine colors. The cut must manage both the stone’s double refraction and its tendency to show wear along facet edges.
• Market trends significantly influence value, with blue zircons traditionally commanding the highest prices among treated stones. However, collector interest in rare natural colors and untreated specimens has created new premium categories in recent years.

The evaluation of zircon quality requires understanding both traditional gemological factors and the unique characteristics that make this gem special. Its exceptional brilliance, range of colors, and historical significance all contribute to its value in today’s market.

Shopping Guide for December Birthstones

Purchasing a December birthstone requires understanding the unique characteristics and challenges each stone presents. This guide will help you make an informed decision and ensure you get the best value for your investment.

Quality Assessment By Stone Type

When evaluating turquoise, look for even, intense blue color without discoloration. Natural specimens should have a waxy luster, and while most turquoise is stabilized, it’s important to ask about treatments. The matrix patterns should be natural and complement the overall design of the piece.

For tanzanite, the depth of color is crucial – the finest stones show a rich blue with violet undertones. Always examine tanzanite under different lighting conditions, as the color can vary significantly. Clarity should be eye-clean, and be wary of windowing (areas where light passes straight through without reflection).

Zircon requires careful examination of brilliance and fire. Natural colors are generally more valuable than heated ones, though both can be beautiful. Pay special attention to the condition of facet edges and look for any chips, as these are common issues in zircon due to its brittle nature.

Setting Considerations

Turquoise benefits most from protective bezel settings. Silver and yellow gold are traditional choices that complement the stone’s color naturally. Avoid tension settings or any design that leaves edges exposed to impact.

Tanzanite requires protective prong or bezel settings due to its perfect cleavage. It’s best to avoid using tanzanite in rings for daily wear unless the setting provides substantial protection. Pendants and earrings often make better choices for this stone.

Zircon needs protective settings due to its brittleness. Six-prong settings offer good security while allowing maximum light interaction to show off the stone’s exceptional brilliance. Well-designed bezel settings can also work beautifully.

Price Expectations

Turquoise varies widely in price, from $5-$100 per carat for commercial quality to $200-$1000 per carat for high-grade natural specimens from famous mines. The presence of attractive matrix patterns and documented origin from prestigious mines can significantly increase value.

Tanzanite typically ranges from $200-$600 per carat for good quality 1-2 carat stones, increasing to $600-$1000+ per carat for fine quality stones over 3 carats. The larger sizes often show better color, commanding premium prices.

Zircon remains relatively affordable, with commercial quality stones available from $50-$100 per carat. Fine specimens, particularly in rare natural colors, can reach $100-$300 per carat or more.

Treatment Awareness

Most turquoise on the market is stabilized with resins to improve durability. Natural, untreated specimens command premium prices but require more careful handling. Always ask about any treatments and care requirements.

Heat treatment is standard and permanent in tanzanite, enhancing its signature blue-violet color. Unheated stones are extremely rare and command significant premiums when documented.

Zircon commonly undergoes heat treatment, particularly to produce blue colors. Natural colors like honey brown or red are more valuable, though heated blue zircons remain popular and beautiful choices.

The key to successful December birthstone shopping lies in understanding these factors and choosing based on intended use, budget, and personal preference. Work with reputable dealers who provide documentation and clearly disclose treatments. Consider how the piece will be worn and select settings appropriate for each stone’s unique characteristics.

Choosing Your December Birthstone

Selecting among December’s three birthstones offers an opportunity to match personal style, budget, and wearing preferences with distinct gemological characteristics. Each stone brings its own charm and practical considerations, making the choice both exciting and potentially complex for buyers seeking the perfect piece.

• Turquoise offers a rich cultural heritage and unique opaque beauty, making it perfect for those drawn to natural, organic appearances and Native American or Southwestern styles. Its relative affordability and range of patterns allows for dramatic pieces that make strong style statements.
• Tanzanite appeals to lovers of fine colored stones who appreciate both rarity and modern luxury. Its remarkable pleochroism and limited source make it an excellent choice for those seeking something truly special, though its relative softness requires more careful wearing habits.
• Zircon provides exceptional brilliance and a range of colors at generally accessible price points. Its durability makes it suitable for daily wear when properly set, while its historic significance appeals to those interested in both science and symbolism.
• Budget considerations vary significantly among the three stones, with commercial-grade turquoise being most affordable, zircon occupying the middle range, and fine tanzanite commanding premium prices. However, all three offer options across various price points.

The choice of a December birthstone ultimately reflects personal connection to these gems’ unique characteristics. Whether drawn to turquoise’s ancient wisdom, tanzanite’s modern prestige, or zircon’s timeless brilliance, December-born individuals have the luxury of choosing from three distinctly beautiful options that each tell their own fascinating story.

Conclusion

December birthstones offer something truly special in the world of gems – a choice between ancient wisdom, modern discovery, and timeless brilliance. Each stone brings its own remarkable characteristics: turquoise with its rich cultural heritage and distinctive patterns, tanzanite with its mesmerizing blue-violet hues and incredible rarity, and zircon with its exceptional brilliance and range of colors. Together, they represent different aspects of Earth’s ability to create beauty, from the sedimentary processes that form turquoise to the tectonic forces that created tanzanite, and the primordial conditions that gave birth to zircon.

Whether you choose the historical significance of turquoise, the modern luxury of tanzanite, or the ancient brilliance of zircon, each December birthstone offers its own unique way to connect with both Earth’s history and personal style. The variety ensures that everyone born in December can find their perfect match, making these three gems a fitting celebration of the month’s special place in the world of precious stones.