For those born in the final month of the year, the birthstone selection is uniquely abundant and visually diverse. December is represented not by a single gem, but by four distinct stones: Turquoise, Zircon, Tanzanite, and Blue Topaz. Each of these gemstones possesses a unique geological origin, a rich history, and a specific set of gemological properties that appeal to collectors and jewelry enthusiasts alike. While they share a common theme of captivating blue hues—a color often associated with the clear winter skies and icy landscapes of the northern hemisphere—they differ significantly in durability, rarity, and cultural lore. This comprehensive guide explores the history, characteristics, and significance of these four magnificent December birthstones, providing an in-depth look at what makes each one a treasured choice.
The selection of these four stones is a relatively modern development, reflecting the evolution of the birthstone list over time to include more contemporary and accessible gems. Turquoise stands as the ancient traditional choice, while Zircon, Tanzanite, and Blue Topaz were added in later years to offer a wider spectrum of color, value, and style. Understanding the nuances of each allows for an informed selection, whether for a personal collection, a piece of fine jewelry, or a deeper appreciation of the geological wonders our planet produces.
Turquoise: The Ancient Talisman of the Desert
History and Lore
Turquoise is arguably the most historically significant of the December birthstones, with a lineage of use that spans millennia and crosses numerous cultures. Its name is derived from the French expression pierre tourques, or "Turkish stone," reflecting its introduction to Europe from the Ottoman Empire via the Silk Road. However, its origins as a prized gem lie in ancient Persia (modern-day Iran) and the Sinai Peninsula. The pharaohs and other rulers of ancient Egypt adorned themselves with turquoise, and Chinese artisans were carving it into intricate objects more than 3,000 years ago.
Beyond its ornamental value, turquoise has been revered for its perceived protective and beneficial powers. For centuries, it was believed to guarantee health and good fortune to its wearer. A particularly enduring belief, originating in the 13th century, held that turquoise could protect a person from falling, particularly from a horse, and that the stone would break into several pieces in the approach of a disaster, thus sacrificing itself to save its owner. Hindu mystics maintained that seeing a turquoise after beholding the new moon would ensure fantastic wealth. Among Native American cultures, particularly the Apache, turquoise was believed to be found by following a rainbow to its end and was a source of immense spiritual power. Today, it continues to symbolize wisdom, tranquility, and friendship.
Geological Formation and Sources
Turquoise is a semi-translucent to opaque phosphate mineral that is hydrous and contains copper and aluminum. Its signature blue-to-green color is directly influenced by the amount of copper (blue) and iron (green) present in its chemical composition. The gem forms in arid regions of the world, specifically in areas with copper-rich geological formations where acidic, copper-laden water can seep through and react with minerals containing aluminum and phosphorus over millions of years.
This specific geological environment limits turquoise's mining locations. The most significant historical and modern sources include the southwestern United States (Arizona, New Mexico, Nevada), Iran, Egypt, China, Mexico, and parts of Central Asia and Africa. Turquoise is often characterized by the presence of "matrix," which are veins of the host rock (often limonite or ironstone) that remain as remnants of the formation process. These matrix patterns, which can appear in a spiderweb fashion, are highly valued by some collectors and add to the stone's unique character.
Gemological Properties
Turquoise is prized for its distinctive color and opaque appearance, which lends itself beautifully to cabochon cuts. It has a waxy to vitreous (glass-like) luster and is relatively soft compared to other gemstones. On the Mohs scale of hardness, turquoise typically registers between 5 and 6, making it susceptible to scratches and abrasions. This relative softness, combined with its porosity, means that turquoise jewelry should be handled with care. It can be damaged by chemicals, cosmetics, and even prolonged exposure to skin oils and perspiration. For this reason, turquoise is often stabilized with impregnating waxes or resins to enhance its durability and color for use in jewelry.
Symbolism and Metaphysical Beliefs
The metaphysical beliefs surrounding turquoise are as ancient as the stone itself. It is widely regarded as a master healing stone, promoting inner calm and serenity. It is associated with the throat chakra, enhancing clear and honest communication. Spiritually, it is believed to attune the wearer to the energies of the earth and sky, fostering a connection between the physical and spiritual worlds. Its protective qualities remain central to its lore, making it a popular talisman for travelers and those seeking safety and good fortune.
Care and Cleaning
Due to its porous nature and relatively low hardness, turquoise requires careful maintenance. It should be cleaned with warm, soapy water and a soft brush. Ultrasonic and steam cleaners are not recommended, as the heat and vibrations can cause cracking or discoloration. It is best to avoid prolonged contact with lotions, perfumes, and other chemicals, which can alter the stone's color over time. When storing turquoise, keep it separate from other jewelry to prevent scratching.
Zircon: The Multicolored Gem of Ancient Fire
History and Lore
Zircon is one of the oldest gemstones on Earth, with crystals dating back billions of years. It is often confused with the much more common and less valuable cubic zirconia (CZ), a lab-created simulant, but they are entirely different minerals. Natural zircon is a legitimate and historically significant gemstone. It was introduced as an official December birthstone in 1952, adding a brilliant and durable option to the list.
Despite its long history, the lore of zircon is less documented than that of turquoise. However, its high refractive index and exceptional brilliance have long been admired. In the Middle Ages, zircon was believed to promote honor and prosperity in the wearer and to bring rest and protection from bad dreams. The stone's name is thought to be derived from the Persian word zargun, meaning "gold-colored," though zircon occurs in a wide array of colors.
Geological Formation and Sources
Zircon is a zirconium silicate mineral that forms within igneous and metamorphic rocks. It is a heavy, durable crystal that is highly resistant to weathering. This resistance makes it one of the few minerals that survive the journey from their original rock source to be deposited as sediment, making it a key mineral in geochronology for dating the age of the Earth's crust.
Zircon is mined in many locations worldwide, including Thailand, Sri Lanka, Australia, Cambodia, Brazil, and Nigeria. While zircon occurs in many colors, the blue variety is most often associated with the December birthstone. It is important to note that most blue zircon on the market today has been heat-treated from its natural brownish color to achieve its desirable blue hues.
Gemological Properties
Zircon possesses a set of gemological properties that make it a fine-quality gemstone, despite its relative obscurity in the modern market.
| Property | Zircon |
|---|---|
| Chemical Formula | ZrSiO₄ |
| Mohs Hardness | 6.5 - 7.5 |
| Refractive Index | 1.92 - 2.01 |
| Crystal System | Tetragonal |
| Luster | Adamantine (Brilliant) |
Its most notable feature is its high refractive index, which is higher than that of a diamond, giving it an exceptional brilliance and "fire." Zircon also has a high dispersion, the property that separates white light into its spectral colors. However, it is somewhat brittle and can be prone to chipping if knocked hard, so protective settings are recommended for rings. It ranks 6.5 to 7.5 on the Mohs scale, making it reasonably durable for most jewelry applications.
Symbolism and Metaphysical Beliefs
Zircon is associated with honor, wisdom, and prosperity. It is believed to help with spiritual grounding and to aid in overcoming negative feelings. The blue variety, in particular, is linked to clarity of thought and peace of mind. Some believe it can help one to let go of past burdens and move forward with renewed purpose.
Care and Cleaning
Zircon's brittleness requires that it be handled with care. It can be cleaned using warm, soapy water and a soft brush. While it is generally safe to use an ultrasonic cleaner, it is best to avoid sudden temperature changes, as zircon can be susceptible to thermal shock. Steam cleaning is not recommended.
Tanzanite: The Vibrant Violet-Blue Sensation
History and Lore
Tanzanite is the newest of the December birthstones, having been commercially discovered in the mid-20th century. It is found in only one location on Earth: the Merelani Hills of Northern Tanzania, near the base of Mount Kilimanjaro. This extreme rarity—sources state it is 1,000 times rarer than diamond—makes it a "gemstone of a generation," with a finite supply. It was officially named after its country of origin by Tiffany & Co., who introduced it to the world in 1968 and hailed it as "the most beautiful blue gemstone discovered in 2,000 years."
Tanzanite was added to the official modern birthstone list in 2002. In many cultures, it is believed to aid in transformation and spiritual awareness, making it a stone for those undergoing significant life changes. It is also the official gemstone for a 24th wedding anniversary.
Geological Formation and Sources
Tanzanite is a variety of the mineral zoisite and owes its unique blue-violet color to trace amounts of vanadium within its chemical structure. The conditions required for its formation are exceptionally rare, involving a unique combination of heat, pressure, and specific geological elements that occurred only in a small area of Tanzania. Most tanzanite found today is heat-treated to achieve its saturated violet-blue color; without this treatment, the stone would typically be a brownish color.
Gemological Properties
Tanzanite is celebrated for its trichroism, a property where the stone displays three different colors when viewed from three different crystallographic directions: blue, violet, and reddish-violet. This gives the gem a complex and dynamic color play that is highly sought after.
| Property | Tanzanite |
|---|---|
| Chemical Formula | Ca₂Al₃(SiO₄)₃(OH) |
| Mohs Hardness | 6 - 7 |
| Refractive Index | 1.69 - 1.70 |
| Crystal System | Orthorhombic |
| Luster | Vitreous to Adamantine |
With a Mohs hardness of 6 to 7, tanzanite is softer than sapphires and rubies but harder than turquoise. It has good toughness but can be susceptible to chipping if struck, so it is often recommended for earrings and pendants rather than rings that receive daily wear.
Symbolism and Metaphysical Beliefs
Tanzanite is strongly associated with spiritual growth, emotional vitality, and intuitive wisdom. Its mix of blue and violet is said to connect to the Crown Chakra, symbolizing both serenity and strength. It is believed to enhance communication with higher spiritual realms and to facilitate a deeper understanding of one's purpose.
Care and Cleaning
Tanzanite should be handled with care due to its relative softness and brittleness. It can be cleaned with warm, soapy water and a soft brush. Ultrasonic and steam cleaners should be avoided, as the vibrations and heat can cause damage. Protective settings, such as bezels, are ideal for tanzanite jewelry to prevent impact.
Blue Topaz: The Brilliant and Abundant Beauty
History and Lore
While topaz in general has a long history, blue topaz is a more modern addition, introduced to the December birthstone list in 1952 alongside zircon. The name "topaz" is believed to derive from the Sanskrit word for "fire." Historically, topaz was often confused with other yellow and golden stones, but the brilliant blue varieties we know today are a more recent development in the gem market.
Blue topaz is not naturally found in the intense, saturated blues often seen in jewelry; it is typically the result of treating naturally colorless topaz. Despite this, it has become one of the most popular and accessible blue gemstones, valued for its exceptional clarity and brilliance.
Geological Formation and Sources
Topaz is a silicate mineral composed of aluminum and fluorine. It forms in igneous rocks, particularly in pegmatites and vapor-rich cavities in granites. Large, colorless crystals are found in various locations, including Brazil, Nigeria, Sri Lanka, and Mexico.
The vibrant blue color associated with December's birthstone is achieved through irradiation and heat treatment of colorless topaz. This process is stable and permanent, making the gem suitable for lifelong wear. The market has developed several distinct trade names for different shades of blue topaz:
- Sky Blue Topaz: A light, airy aqua color reminiscent of clear skies.
- Swiss Blue Topaz: A vibrant, medium-light blue with a high saturation.
- London Blue Topaz: A deep, inky, and often very dark blue that is highly prized by collectors.
Gemological Properties
Topaz is a hard and durable gemstone, making it an excellent choice for all types of jewelry, including rings that are worn daily. It has a glass-like luster and is known for its exceptional clarity.
| Property | Topaz |
|---|---|
| Chemical Formula | Al₂(F,OH)₂SiO₄ |
| Mohs Hardness | 8 |
| Refractive Index | 1.61 - 1.63 |
| Crystal System | Orthorhombic |
| Luster | Vitreous |
With a hardness of 8 on the Mohs scale, blue topaz is quite resistant to scratching. However, it does possess "deep cleavage," meaning it can be split along internal planes if struck with sufficient force. This makes it somewhat delicate despite its hardness, and care should be taken to avoid sharp impacts.
Symbolism and Metaphysical Beliefs
Blue topaz is associated with calm, clarity, and communication. It is believed to soothe the mind, relieve stress, and promote truthful expression. The different shades of blue are sometimes linked to different energies, with the lighter blues promoting peace and tranquility, and the deeper London Blue associated with wisdom and a connection to the earth.
Care and Cleaning
Blue topaz is relatively easy to care for. It can be cleaned with warm, soapy water and a soft brush. It is generally safe to use an ultrasonic cleaner, but steam cleaning should be avoided due to the potential for thermal shock. As with all gemstones, it is best to avoid harsh chemicals and sudden temperature changes.
Conclusion
The four birthstones of December—Turquoise, Zircon, Tanzanite, and Blue Topaz—offer a remarkable range of choices for anyone born in the last month of the year. From the ancient, opaque, and protective talisman of Turquoise to the brilliant, multi-hued, and ancient fire of Zircon; from the rare, modern, and transformative vibrancy of Tanzanite to the accessible, durable, and sky-clear brilliance of Blue Topaz, each gem possesses a unique story and set of characteristics. This diversity allows for a personal selection based on individual preference for color, durability, historical significance, and value. Together, they represent the cool, clear, and captivating beauty of winter, making them enduringly popular and cherished gems in the world of fine jewelry.