December holds a unique distinction in the world of birthstones. While most months are associated with a single gem, December boasts four officially recognized stones: Turquoise, Zircon, Tanzanite, and Blue Topaz. This abundance offers those born in the final month of the year a diverse palette of colors and characteristics, all united by a cool, wintry aesthetic reminiscent of icy skies and deep twilight. The evolution of this list, from ancient traditions to modern commercial appeal, tells a story of changing tastes, new discoveries, and the enduring human fascination with the color blue.
The tradition of assigning gemstones to specific months has roots stretching back to ancient civilizations, but the modern standardization began in 1912 with the National Association of Jewelers. This list has been updated over time, with the most recent addition, Tanzanite, occurring in 2002. The result is a "treasure chest" of options, each with its own distinct history, geological origin, and symbolic meaning. This article provides an in-depth exploration of these four remarkable gemstones, examining their gemological properties, historical lore, and practical considerations for collectors and jewelry enthusiasts.
Turquoise: The Ancient Amulet
Turquoise is perhaps the most historically significant of December's birthstones, a gem cherished for millennia by cultures across the globe. It is a semi-translucent to opaque phosphate mineral that derives its name from the French "pierre tourques," or "Turkish stone," reflecting its historical trade route through Turkey. Its color spectrum ranges from a serene sky blue to a verdant greenish hue, often intersected by a distinctive matrix of the host rock in which it formed.
History and Lore
The history of turquoise is as rich and varied as its color. Ancient Egyptian pharaohs adorned themselves with turquoise jewelry, and Chinese artisans were carving the stone more than 3,000 years ago. Its protective powers have been a central theme throughout its lore. From the 13th century onward, it was widely believed to safeguard the wearer from falls, particularly from horses, and was thought to shatter upon the approach of disaster as a final act of protection. Hindu mystics believed that viewing a turquoise after seeing the new moon would ensure immense wealth. In North America, the Apache people held that turquoise could be found by following a rainbow to its end, imbuing the gem with a celestial and mystical quality.
Symbolism and Metaphysical Beliefs
The symbolic meaning of turquoise is deeply connected to protection and tranquility. It is often seen as a steadying force, a gem that provides grounding and a sense of calm during chaotic times. Many view it as a talisman for good fortune and health, a belief that has persisted for centuries. Its color, reminiscent of a clear winter sky, reinforces its association with peace and clarity of mind.
Geological Formation and Sources
Turquoise is a secondary mineral that forms when water containing copper, aluminum, and phosphorus seeps through pre-existing rocks. This process occurs in arid regions, which is why its primary sources are located in dry climates. While specific modern mining locations are not detailed in the provided materials, the gem's historical presence in Egypt and China, along with its association with Native American cultures in the American Southwest, points to a long history of extraction in these regions.
Gemological Properties
- Hardness: On the Mohs scale, turquoise has a hardness of 5 to 6. This makes it relatively soft compared to other gemstones.
- Durability: It is porous and can be susceptible to cracking, especially if subjected to heat or chemical exposure. Its softness and porosity make it less suitable for rings worn daily without careful mounting and maintenance.
- Appearance: Ranges from semi-translucent to opaque with a characteristic waxy to vitreous luster. The presence of matrix (veins of the host rock) is a common and often desirable feature.
Care and Cleaning
Due to its moderate hardness and porosity, turquoise requires gentle care. It should be protected from harsh chemicals, including cosmetics and perfumes, which can alter its color. Cleaning should be done with warm, soapy water and a soft brush. Avoid ultrasonic and steam cleaners.
Zircon: The Diamond Simulant with a Rich Past
Often confused with the synthetic cubic zirconia, natural zircon is one of the oldest minerals on Earth and a gem of immense brilliance and historical significance. It is a zirconium silicate that occurs in a wide variety of colors, but the bright, clear blue variety is the one traditionally associated with December.
History and Lore
The etymology of the word "zircon" is a subject of scholarly debate. Some trace it to the Arabic zarkun ("cinnabar" or "vermilion"), while others point to the Persian zargun ("gold colored"). Both origins seem plausible given the gem's broad color palette, which includes red, orange, yellow, brown, green, and blue. For centuries, colorless zircon has been mistaken for diamond due to its exceptional brilliance and "fire"—the flashes of multicolored light it exhibits. This confusion was particularly common before the advent of modern gemology.
During the Middle Ages, zircon was believed to possess the power to induce deep sleep and ward off evil spirits. It holds a significant place in Hindu tradition as one of the nine gems, or navaratna, alternating with hessonite garnet. When worn together, these nine gems were said to protect the wearer and bestow wealth, wisdom, and good health. The Victorian era saw a particular fondness for blue zircon, further cementing its place in jewelry history.
Symbolism and Metaphysical Beliefs
Zircon is associated with mental acuity and emotional balance. Its symbolic meaning is linked to sharpening focus, boosting mental clarity, and fostering a sense of wisdom. It is also connected to a feeling of balance, helping the wearer navigate complex situations with a clear mind.
Geological Formation and Sources
Zircon is a primary mineral found in igneous and metamorphic rocks. It is highly resistant to weathering and is often found in sedimentary deposits as well. The provided materials do not specify modern mining locations for blue zircon, but it is known to be sourced from various locations worldwide, including Cambodia, Sri Lanka, and Australia.
Gemological Properties
- Hardness: Zircon has a hardness of 6.5 to 7.5 on the Mohs scale, making it a relatively durable gem, though not as hard as topaz or sapphire.
- Durability: It has fair to good toughness, but its brittleness means it can be chipped or abraded if knocked against a hard surface. It is sensitive to sudden temperature changes.
- Appearance: Zircon is known for its high refractive index (2.4), which gives it exceptional brilliance and fire, and a high dispersion of 0.039. It can be heat-treated to produce a stable blue color.
Care and Cleaning
Zircon can be cleaned with warm, soapy water and a soft brush. It is advisable to avoid ultrasonic cleaners and sudden temperature changes, which can cause fractures. Due to its brittleness, zircon jewelry should be stored carefully to prevent scratching or impact damage.
Tanzanite: The Modern Marvel
Tanzanite is the newest and rarest of December's birthstones, a relative newcomer to the gemological world that has captured the market with its unique beauty. Discovered in the 20th century, its journey from a single source to a globally recognized gem is a story of modern rarity and allure.
History and Lore
Tanzanite's history is brief but dramatic. It was discovered in the Merelani Hills of Tanzania in the late 1960s and was subsequently introduced to the market by Tiffany & Co., who recognized its potential and named it after its country of origin. Its addition to the official birthstone list in 2002 solidified its status. Lacking ancient lore, its symbolism is largely modern and tied to its discovery story. It is often associated with transformation, growth, and new beginnings, its blue-violet tones reflecting the clarity and curiosity of stepping into a fresh chapter of life.
Symbolism and Metaphysical Beliefs
As a modern gem, tanzanite's metaphysical beliefs are contemporary. It is linked to shifts and personal growth. Its unique color, which shifts from violet to blue depending on the lighting and viewing angle, is seen as a reflection of its meaning: embracing change and seeing things from a new perspective.
Geological Formation and Sources
Tanzanite's rarity is a direct result of its extremely limited geological origin. It is found in only one location on Earth: a small, four-square-kilometer mining area in the Merelani Hills of northern Tanzania, near the base of Mount Kilimanjaro. It forms as a result of a unique geological event where specific minerals were subjected to intense heat and pressure, altering them into the blue-violet zoisite we know as tanzanite.
Gemological Properties
- Hardness: On the Mohs scale, tanzanite has a hardness of 6.5 to 7. Its softness makes it less suitable for rings intended for daily wear.
- Durability: It has fair to good toughness but is susceptible to abrasion and chipping. It is also sensitive to heat, which can cause permanent color changes.
- Appearance: Known for its strong trichroism, displaying blue, violet, and burgundy hues simultaneously. The most desirable color is a rich, saturated violet-blue. Most tanzanite is heat-treated to achieve its stable blue color, a process that is permanent and does not affect durability.
Care and Cleaning
Tanzanite requires careful handling. It is best set in earrings or pendants rather than rings. If used in a ring, a protective mounting is essential. Cleaning should be done with warm, soapy water. Ultrasonic and steam cleaners are strictly forbidden as they can damage the stone.
Blue Topaz: The Durable Blue
Blue topaz, with its crisp, icy blue hue, is the most durable of December's birthstones, offering an affordable and resilient option for everyday jewelry. While natural blue topaz exists, much of the vibrant blue topaz on the market today is the result of irradiation and heat treatment of a colorless or pale topaz.
History and Lore
The exact historical origin of blue topaz is difficult to trace, as topaz in general has been known and confused with other yellow gemstones throughout history. Its identity as a distinct blue gem is a more modern phenomenon. Its significance is less tied to ancient legends and more to its modern appeal as a durable and beautiful blue stone.
Symbolism and Metaphysical Beliefs
The provided materials do not specify unique symbolic meanings for blue topaz beyond its general association with the color blue and the winter season. However, topaz in general has often been associated with strength, wisdom, and good health.
Geological Formation and Sources
Blue topaz is mined in several countries, including Sri Lanka, Brazil, Mexico, Nigeria, and the United States. It is the official state gem of Texas, highlighting its significance in the U.S. Topaz is a silicate mineral that forms in igneous rocks, particularly in pegmatites and rhyolites.
Gemological Properties
- Hardness: Blue topaz has a hardness of 8 on the Mohs scale, making it the hardest and most durable of the four December birthstones. This makes it highly resistant to scratching and suitable for everyday wear in all types of jewelry.
- Durability: It has good toughness, though large crystals can be cleaved if struck hard. It is generally stable under normal conditions.
- Appearance: It ranges from a light, sky blue to a deep, saturated "Swiss Blue" or "London Blue" color. Its clarity is typically excellent, with few inclusions. It has a vitreous luster.
Care and Cleaning
Blue topaz is easy to care for. It can be cleaned with warm, soapy water and is generally safe for ultrasonic cleaners, though caution is advised for stones with fractures. It is also stable under steam cleaning. Its durability makes it a practical choice for rings, bracelets, and other frequently worn jewelry.
Comparative Overview of December Birthstones
To provide a clear comparison of these four gems, the following table summarizes their key gemological properties and characteristics based on the provided sources.
| Gemstone | Hardness (Mohs) | Durability & Care | Primary Color(s) | Rarity & Value |
|---|---|---|---|---|
| Turquoise | 5 - 6 | Moderate. Porous, susceptible to chemicals and heat. Clean with warm, soapy water. | Sky blue to greenish-blue, often with matrix. | Historically significant, common to rare depending on quality. |
| Zircon | 6.5 - 7.5 | Fair to good. Brittle, sensitive to temperature changes. Avoid ultrasonics. | Bright, clear blue (heat-treated). | Naturally occurs in many colors; blue variety is popular. |
| Tanzanite | 6.5 - 7 | Fair to good. Soft, sensitive to heat and abrasion. Avoid ultrasonics and steam. | Rich violet-blue to blue-violet (trichroic). | Extremely rare; found in only one location. The most valuable. |
| Blue Topaz | 8 | Good. Very durable and hard. Suitable for everyday wear. | Light to deep, saturated blue. | Common and affordable, especially after treatment. |
Conclusion
December's four birthstones offer an unparalleled variety for those born in the month. From the ancient, protective amulet of Turquoise to the brilliant, diamond-like fire of Zircon, the rare, modern allure of Tanzanite, and the durable, icy blue of Topaz, each gem presents a unique story and set of characteristics. The expansion of the birthstone list to include these four stones reflects a tradition that adapts to new discoveries and market desires while honoring historical significance. Whether chosen for its symbolic meaning, geological rarity, or simply its beauty, a December birthstone is a piece of the earth's artistry, a cool blue echo of the winter month from which it draws its name.