December, the final month of the year, is symbolically rich with closure and renewal. Its birthstones reflect this duality, embodying not just the beauty of blue hues but also the deep-rooted historical and symbolic significance that these gems carry. Among the officially recognized birthstones for December are Turquoise, Tanzanite, and Blue Zircon, with Blue Topaz sometimes cited as an alternative. Each of these gemstones has its own geological story, cultural lore, and metaphysical meaning, making the December birthstone group one of the most diverse and historically rich in the gemstone calendar.
This article delves into the December birthstones, focusing particularly on Turquoise, which is the traditional and most widely recognized December birthstone. However, the December 31st birthstone is a unique combination of Tanzanite, Turquoise, and Zircon, each with its own significance. This piece explores the color, history, geological properties, cultural symbolism, and modern use of these gemstones, with a special emphasis on their association with the final day of the year.
History and Lore
The December birthstone tradition has ancient roots, with Turquoise being one of the earliest known gemstones used in jewelry and ritual. Turquoise has been mined and cherished for over 6,000 years, with archaeological evidence showing its use in ancient Egypt, Mesopotamia, and Mesoamerica. The name Turquoise is derived from the French pierre turquoise, meaning “Turkish stone,” as it was first brought to Europe via Turkish bazaars during the medieval period.
The ancient Egyptians believed Turquoise to be a protective stone, often embedding it in amulets and jewelry to ward off evil and promote health. Pharaohs were buried with Turquoise items, suggesting its spiritual significance. In the 13th century, it was believed that Turquoise could protect the wearer from falling, especially from horses, and would break into pieces when danger was near. Hindu mystics even believed that gazing at Turquoise after the new moon would bring wealth.
Zircon, another December birthstone, has an even older history. Some zircon crystals have been dated to over 4.4 billion years old, making them among the oldest minerals on Earth. In the Middle Ages, physicians wore zircon on their left fingers, believing it aided in accurate diagnosis. Zircon was also used as an amulet against the Black Death in Europe. In India, zircon was thought to be more powerful when set in gold.
Tanzanite, by contrast, is a modern discovery, first identified in the 1960s in Tanzania. Its discovery marked a significant event in gemology, as it was the first new gemstone to be discovered in over two centuries. Marketed as a “December birthstone” in the 1970s, Tanzanite quickly gained popularity for its rich violet-blue color and its association with success and prosperity.
Geological Formation and Sources
Each December birthstone has a unique geological origin and source, which influences its availability, color, and value.
Turquoise
Turquoise is a hydrated phosphate of aluminum and copper. Its formation begins when groundwater rich in copper and phosphorus seeps into rock formations, particularly in arid and semi-arid environments. Over time, these minerals react with surrounding rock, forming the characteristic blue and green hues of Turquoise. The veins and matrix patterns visible in the stone are remnants of the original rock, making each Turquoise gemstone unique.
Historically, the most prized Turquoise came from the United States, particularly from the Southwest (e.g., Arizona and Nevada). Other significant sources include China, Egypt, Iran, and Mexico. The softness of Turquoise (Mohs hardness of 5–6) makes it vulnerable to damage from water, oils, and abrasion, so it is often stabilized or treated with resins to enhance its durability.
Zircon
Zircon is a zirconium silicate that occurs in a wide range of colors, including colorless, yellow, red, and blue. The blue variety, which is often used as a December birthstone, is typically created through heat treatment. Natural zircon is found in several countries, with major sources including Thailand, Cambodia, Vietnam, Sri Lanka, and South Africa. Zircon has a high refractive index and excellent brilliance, which has made it a popular diamond substitute. Some zircons contain trace amounts of uranium and thorium, making them valuable in geological dating studies.
Tanzanite
Tanzanite is a rare gemstone formed from the mineral zoisite, which undergoes a transformation due to heat and pressure. The only known source of Tanzanite is the Merelani Hills in northern Tanzania, where it was first discovered in the 1960s. Tanzanite’s unique violet-blue color is due to the presence of vanadium. It has a relatively high hardness (6–7 on the Mohs scale), making it suitable for everyday jewelry.
Gemological Properties
Understanding the physical and optical properties of each December birthstone is essential for gemologists, jewelers, and collectors.
| Gemstone | Color | Hardness (Mohs) | Composition | Refractive Index | Origin |
|---|---|---|---|---|---|
| Turquoise | Blue to green with matrix | 5–6 | Hydrated phosphate of aluminum and copper | 1.61–1.65 | United States, China, Iran |
| Zircon | Blue, colorless, red, yellow | 6.5–7.5 | Zirconium silicate | 1.92–2.00 | Thailand, Cambodia, Vietnam |
| Tanzanite | Violet-blue | 6–7 | Calcium aluminum silicate (zoisite) | 1.694–1.701 | Tanzania |
Turquoise
- Color: Ranges from sky blue to greenish-blue, often with black or brown matrix patterns.
- Hardness: 5–6, relatively soft and susceptible to damage.
- Luster: Waxy to sub-vitreous.
- Specific Gravity: 2.6–2.8.
- Transparency: Opaque to semi-translucent.
Turquoise is often stabilized with resins or oils to enhance its durability and color. This treatment is usually permanent but should be considered when assessing the stone's value.
Zircon
- Color: Available in many colors, with blue zircon being the most popular for December.
- Hardness: 6.5–7.5, relatively durable.
- Luster: Vitreous.
- Specific Gravity: 4.6–4.8.
- Transparency: Transparent to translucent.
- Refractive Index: 1.92–2.00, which gives it a high level of brilliance.
Zircon has a strong birefringence (double refraction), which can cause a visible doubling of facets in some cuts. This effect is more pronounced in certain colors and cuts.
Tanzanite
- Color: Deep violet-blue with a pleochroic effect (appearing different colors in different directions).
- Hardness: 6–7, suitable for jewelry.
- Luster: Vitreous.
- Specific Gravity: 3.1–3.4.
- Transparency: Transparent to translucent.
- Refractive Index: 1.694–1.701.
Tanzanite's pleochroism means that it can display blue, purple, and red hues depending on the angle of light. This effect is one of the reasons it is so visually striking.
Symbolism and Metaphysical Beliefs
Each December birthstone carries its own symbolic and spiritual significance, which has been passed down through centuries.
Turquoise
Turquoise has long been associated with prosperity, success, and protection. In ancient Egypt, it was believed to bring good fortune and was often used in amulets and talismans. In medieval Europe, it was thought to protect against falls and accidents, especially when riding horses. Some cultures believed that Turquoise would break into pieces before a disaster struck, serving as a warning.
Modern metaphysical beliefs attribute calming and centering properties to Turquoise. It is often used in meditation and spiritual healing practices to promote emotional balance and communication. In some cultures, Turquoise is considered a love charm, especially in Russia, where it is popular in wedding rings.
Zircon
Zircon has a long history of being used in healing and spiritual practices. In the Middle Ages, physicians wore zircon on their left fingers, believing it helped in making accurate diagnoses. It was also used as an amulet against the Black Death in Europe. In India, zircon was thought to be more powerful when set in gold.
Zircon is believed to enhance mental clarity and focus, making it a popular stone for students and professionals. It is also associated with inner strength and transformation, helping the wearer to overcome obstacles and grow emotionally.
Tanzanite
Tanzanite is often associated with emotional healing, intuition, and spiritual awakening. It is believed to help the wearer release emotional blockages and connect with their inner self. Because it was discovered in the 20th century, Tanzanite is also associated with modern innovation and renewal.
Tanzanite is sometimes called the “stone of transformation,” helping individuals to let go of the past and embrace new beginnings. It is also believed to enhance communication and understanding, making it a popular stone for relationships and personal growth.
Care and Cleaning
Each December birthstone requires specific care to preserve its beauty and longevity.
Turquoise
Turquoise is relatively soft (5–6 on the Mohs scale) and can be easily damaged by water, oils, and abrasives. It should be kept away from direct sunlight, which can cause it to fade or dry out. Cleaning should be done with a soft, dry cloth. Avoid using water or ultrasonic cleaners, as these can damage the stone.
Zircon
Zircon is more durable than Turquoise but still requires gentle handling. It can be cleaned with a soft brush and mild soap solution, followed by a gentle rinse and drying with a soft cloth. Avoid using harsh chemicals or steam cleaners, as these can affect the stone’s luster.
Tanzanite
Tanzanite is relatively hard (6–7 on the Mohs scale) and can be cleaned with a soft brush and mild soap solution. It should be kept away from harsh chemicals and extreme temperatures, as these can affect its color and clarity.
Conclusion
The December birthstones—Turquoise, Tanzanite, and Blue Zircon—offer a rich tapestry of history, beauty, and symbolism. Each gemstone has its own unique story, from the ancient use of Turquoise in amulets and jewelry to the modern discovery of Tanzanite in Tanzania. These stones are not only cherished for their aesthetic appeal but also for their deep cultural and spiritual significance.
As a December birthstone, Turquoise holds a special place in the hearts of many, symbolizing success, prosperity, and protection. Its soft blue hues and intricate matrix patterns make it a timeless gemstone that continues to captivate collectors and jewelry lovers alike.