December, the final month of the year, is uniquely blessed with three official birthstones: turquoise, tanzanite, and zircon—with blue zircon being the most commonly referenced variety. This multiplicity reflects the rich and evolving history of birthstone symbolism, which has been shaped by cultural, historical, and commercial influences over centuries. While December is associated with the end of the year and the winter solstice, its birthstones carry meanings of protection, wisdom, and transformation, making them a fitting tribute to the reflective and hopeful spirit of the season.
In this article, we delve into the history, geological properties, symbolism, and care of these three gemstones. We also explore their cultural significance, sources, and modern popularity, offering a comprehensive look at what makes them special.
History and Lore
The concept of birthstones has ancient roots, with some lists tracing back to biblical times. The earliest known references appear in Exodus 28:17–20, where 12 stones are listed for the high priest’s breastplate. However, the modern list of birthstones has evolved significantly over time, with various organizations and jewelers adding or replacing gems based on new discoveries, changing trends, and cultural shifts.
December’s birthstones have undergone a particularly dynamic transformation. While the earliest references to December’s gemstones included ruby, modern listings have seen the inclusion of turquoise, zircon, and tanzanite.
Here is a timeline of the evolution of December's birthstones:
- 1870: Turquoise was first listed as the December birthstone by Tiffany & Co.
- 1912: Turquoise remained the primary December birthstone, with lapis lazuli as an alternative, as listed by the National Association of Jewellers (now Jewellers of America).
- 1952: Zircon was added to the December list by the Jewelry Industry Council of America.
- 2002: Tanzanite was officially added to the list, reflecting its recent discovery and rising popularity.
This evolution highlights the dynamic nature of birthstone lore, where gemstones are not only valued for their beauty but also for their cultural, symbolic, and historical significance.
Ancient and Cultural Significance
Turquoise, one of the oldest and most revered gemstones, has been cherished for thousands of years. It was highly valued in ancient Egypt, where it was used in jewelry and amulets. Pharaohs and high-ranking officials adorned themselves with turquoise as a symbol of divine favor, protection, and prosperity. The stone was often set into gold or carved into intricate pendants and inlays.
In China, turquoise was used as early as 3000 BCE, where it was carved into pendants and religious artifacts. Chinese artisans considered it a stone of wisdom and immortality, often linking it to the heavens.
Native American cultures, particularly the Navajo and Zuni, also hold turquoise in high esteem. It was believed to bring good fortune, protection, and spiritual connection. Turquoise was often used in healing rituals and as a medium for connecting with the divine.
Zircon, a mineral that has existed since the Archean Eon, is known for its rainbow-like color changes and has been revered in various parts of the world. In medieval Europe, it was often mistaken for diamonds or topaz, and it was believed to bring wisdom and divine insight. Some sources suggest that zircon was used in alchemy and mysticism, with the belief that it could enhance spiritual awareness.
Tanzanite, the newest of the December birthstones, was discovered in 1967 in Tanzania, making it the youngest gemstone ever added to the birthstone list. Its discovery was serendipitous; a local Maasai tribesman found the first crystals in the Merelani Hills, near Mount Kilimanjaro. The gem was identified as a variety of zoisite and was named tanzanite in honor of its country of origin. By 1968, Tiffany & Co. had launched an aggressive marketing campaign that helped tanzanite gain international recognition.
Tanzanite's velvety blue to violet hues and its pleochroism—the ability to display multiple colors when viewed from different angles—have made it a fashionable and highly sought-after gemstone.
Geological Formation and Sources
Each of December’s birthstones has a unique geological origin and is found in specific locations around the world.
Turquoise
Turquoise is a phosphate mineral that forms in cave-like pockets within limestone and sandstone. It is typically found in arid regions where alkaline groundwater interacts with copper minerals. The resulting deposits are often found in open pits or veins and require careful mining.
Primary sources for turquoise include:
- Iran (historically the most famous source)
- United States (particularly New Mexico, Arizona, and Nevada)
- China
- Egypt
- Russia
- Australia
The color of turquoise is determined by the presence of copper (blue) and iron (green). Matrix—the dark veins of rock that run through the stone—can also affect the appearance and value of turquoise. Stones with a deep blue color and minimal matrix are the most valuable.
Tanzanite
Tanzanite is a variety of zoisite, a calcium aluminum silicate. It is only found in Tanzania, making it one of the rarest gemstones in the world. The Merelani Hills, located in northern Tanzania, are the only commercial source of tanzanite.
The gemstone forms under high pressure and temperature conditions, typically in metamorphic rock formations. Tanzanite is pleochroic, meaning it displays different colors when viewed from different angles—blue, violet, and sometimes brown. This property makes it particularly visually interesting and valuable.
Tanzanite is mined in open pits, with some operations reaching depths of over 100 meters. The mines are often manually operated, with thousands of workers involved in the extraction process. The limited supply and geographic exclusivity of tanzanite contribute to its high market value and collectibility.
Zircon
Zircon is a zirconium silicate that forms in a variety of igneous and metamorphic rocks. It is one of the oldest minerals on Earth, with some zircon crystals dating back over 4.4 billion years.
Zircon is found in numerous countries, including:
- Sri Lanka
- Australia
- Myanmar (Burma)
- Vietnam
- Cambodia
- Brazil
- United States
- India
Zircon is often found in association with sapphire sources, and it is commonly heat-treated to enhance its color. The most popular variety is blue zircon, which is used in December birthstone jewelry.
Zircon is not as hard as diamond or corundum, with a hardness of 6 to 7.5 on the Mohs scale. This means it can be prone to scratches and abrasion, and it requires gentle handling and cleaning.
Gemological Properties
Understanding the physical and optical properties of each birthstone is essential for identifying, purchasing, and caring for these gems. Below is a detailed breakdown of the key gemological characteristics of each December birthstone.
Turquoise
| Property | Description |
|---|---|
| Chemical Formula | CuAl₆(PO₄)₄(OH)₈·4H₂O |
| Hardness (Mohs Scale) | 5–6 |
| Color | Blue to green, often with matrix patterns |
| Luster | Waxy to dull |
| Transparency | Opaque to semi-transparent |
| Specific Gravity | 2.6–2.8 |
| Refractive Index | 1.61–1.65 |
| Origin of Color | Copper (blue), iron (green) |
Turquoise is relatively soft, making it susceptible to scratches and damage. It is also porous, so it can be affected by heat, chemicals, and moisture. Proper care is essential to maintain its color and luster.
Tanzanite
| Property | Description |
|---|---|
| Chemical Formula | Ca₂Al₃(SiO₄)(OH)₃ |
| Hardness (Mohs Scale) | 6–7 |
| Color | Blue, violet, sometimes brown (pleochroic) |
| Luster | Vitreous to sub-vitreous |
| Transparency | Transparent to translucent |
| Specific Gravity | 3.1–3.4 |
| Refractive Index | 1.690–1.705 |
| Origin of Color | Vanadium and chromium |
Tanzanite is pleochroic, meaning it displays different colors when viewed from different angles. The most valuable color is a deep blue with a violet secondary hue. Tanzanite is relatively stable, but it can be affected by exposure to heat, which may cause color fading.
Zircon
| Property | Description |
|---|---|
| Chemical Formula | ZrSiO₄ |
| Hardness (Mohs Scale) | 6–7.5 |
| Color | Colorless, blue, yellow, red, green, brown |
| Luster | Vitreous |
| Transparency | Transparent to translucent |
| Specific Gravity | 4.0–4.7 |
| Refractive Index | 1.92–2.01 |
| Origin of Color | Natural or heat-treated (especially blue zircon) |
Zircon is known for its high refractive index, giving it a sparkling appearance. The blue variety, which is most commonly used in December birthstone jewelry, is heat-treated to enhance its color. Zircon is durable, but it can abrade over time, so it should be handled with care.
Symbolism and Metaphysical Beliefs
December’s birthstones are not only admired for their aesthetic beauty but also for the symbolic and spiritual meanings they carry across cultures and centuries.
Turquoise
Turquoise has long been associated with protection, healing, and spiritual connection. In ancient Egypt, it was believed to ward off evil and bring good fortune. Pharaohs wore turquoise to symbolize divine power and immortality.
In medieval Europe, turquoise was thought to protect the wearer from falling, especially when horseback riding. There was also a belief that the gemstone would break into pieces before a disaster, acting as an early warning.
In Native American traditions, especially among the Zuni and Navajo, turquoise is considered a stone of the sky and water. It is used in ceremonies, healing rituals, and jewelry to promote balance, harmony, and spiritual insight.
Turquoise is also believed to enhance communication and intuition, making it a popular stone for those in creative or spiritual fields.
Tanzanite
Though a modern discovery, tanzanite has quickly become symbolically rich. It is often associated with transformation, intuition, and spiritual awakening. The pleochroism of the gemstone is seen as a metaphor for seeing multiple perspectives and gaining deeper understanding.
Tanzanite is also believed to calm the mind and soothe emotional distress, making it a popular stone for meditation and healing. Some sources suggest that it can enhance creativity and emotional clarity, helping individuals to connect with their inner truth.
As a December birthstone, tanzanite also symbolizes the end of the year and the beginning of a new cycle, making it a fitting gemstone for reflection and renewal.
Zircon
Zircon has a long history of metaphysical significance. In medieval Europe, it was believed to enhance wisdom and divine insight, and it was used in alchemy and mysticism. Some sources suggest that zircon was considered a stone of truth and clarity, helping the wearer to see beyond illusions and distractions.
Zircon is also associated with protection and prosperity. In ancient times, it was thought to ward off negative energies and promote good fortune. The blue variety, which is most commonly used in December birthstone jewelry, is believed to enhance spiritual awareness and emotional balance.
In modern metaphysical practices, zircon is often used to stimulate the third eye and crown chakras, promoting higher consciousness and spiritual growth.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of December’s birthstones. Each gemstone has specific needs based on its hardness, stability, and sensitivity to chemicals and light.
Turquoise
Turquoise is relatively soft and porous, making it susceptible to damage from heat, chemicals, and moisture. To care for turquoise:
- Avoid exposure to water, especially hot water, as it can cause the stone to dry out and lose its color.
- Store it separately from other gemstones to prevent scratching.
- Clean with a soft cloth and avoid using harsh chemicals or ultrasonic cleaners.
- If the stone becomes dull or discolored, it can be lightly polished with a fine-grade polishing cloth.
Turquoise should be worn sparingly in rough conditions, such as gardening, sports, or cleaning.
Tanzanite
Tanzanite is pleochroic and sensitive to heat, which can affect its color over time. To care for tanzanite:
- Avoid exposure to prolonged sunlight or heat, as this can cause the color to fade.
- Clean with a soft brush and warm soapy water.
- Avoid using ultrasonic or steam cleaners, as they can damage the gemstone.
- Store tanzanite separately to prevent scratches from harder gemstones.
Tanzanite should be handled with care and worn in a way that minimizes exposure to harsh conditions.
Zircon
Zircon is relatively durable, but it can be prone to abrasion over time, especially if worn frequently. To care for zircon:
- Clean with a soft brush and warm soapy water.
- Avoid using ultrasonic or steam cleaners, as they can damage the stone.
- Avoid exposure to harsh chemicals, which can damage the surface.
- Store zircon separately from other gemstones to prevent scratches.
Zircon is best worn in a setting that protects it from impact and abrasion.
Conclusion
December’s birthstones—turquoise, tanzanite, and zircon—represent a rich tapestry of history, symbolism, and beauty. From the ancient reverence for turquoise to the modern discovery of tanzanite, each gemstone carries a unique story and significance.
These stones are not only admired for their colors and luster, but also for the spiritual and emotional resonance they offer. Whether you are drawn to the deep blue of turquoise, the velvety hues of tanzanite, or the sparkling brilliance of zircon, there is a December birthstone for every personality and style.
Understanding the geological origins, cultural meanings, and care requirements of these gems allows you to appreciate them more deeply and wear them with confidence and care. As symbols of protection, transformation, and spiritual insight, these December birthstones are a beautiful way to celebrate the end of the year and the new possibilities that lie ahead.