December is a month rich in tradition and symbolism, not least of which is its association with a set of beautiful blue gemstones. These stones—turquoise, tanzanite, zircon, and blue topaz—are each recognized as December’s birthstone, offering a spectrum of blue hues that mirror the icy, wintry palette of the season. While aquamarine is often mistakenly linked to December due to its popular use in jewelry, it is actually the birthstone for March. Despite this, aquamarine rings are frequently marketed as December birthstone jewelry, making it important to distinguish between the official December birthstones and the confusion around aquamarine.
This article delves into the characteristics, history, symbolism, and care of the true December birthstones, with a focus on their gemological properties, cultural significance, and practical use in jewelry. We will also address the role of aquamarine in December-themed jewelry and clarify its actual birthstone month.
History and Lore of December Birthstones
The tradition of associating gemstones with specific months of the year has ancient roots. One of the earliest known references is found in the Biblical Breastplate of Aaron, which listed twelve stones representing the twelve tribes of Israel. While this list did not assign stones to months, it laid the foundation for the later development of the modern birthstone calendar.
By the 20th century, the American National Association of Jewelers (now Jewelers of America) formalized the modern birthstone list in 1912, which has since been revised to reflect new discoveries and cultural preferences. December is unique in having three traditional birthstones: turquoise, zircon, and tanzanite. Blue topaz was later added to the list, likely due to its popularity and durability compared to the more fragile traditional stones.
Each of these stones carries its own set of historical and symbolic meanings. Turquoise, for example, has been used for thousands of years in jewelry and ceremonial objects, particularly in Native American and Egyptian cultures. It was believed to provide protection, wisdom, and spiritual guidance. Zircon, on the other hand, has a long history in ancient jewelry, though it was often confused with hyacinth, a term used in medieval times to describe various red or orange gems.
Tanzanite is the most modern of the four, having only been discovered in 1967 in Tanzania. Its name is derived from the country of its origin, and it quickly became a favorite due to its violet-blue color and affordability compared to other precious gems. Blue topaz, with its clear, icy blue color, was added to the December birthstone lineup in the 1980s and has since become a popular choice for everyday jewelry due to its durability and affordability.
Geological Formation and Sources
Turquoise
Turquoise is a phosphate mineral that forms in hydrothermal veins and weathered deposits, particularly in arid climates. It is typically found in copper-rich environments, where it forms through the interaction of water, copper, and phosphorus. The blue color of turquoise is due to the presence of copper, while the greenish hues come from iron.
Significant sources of turquoise include Nevada and Arizona in the United States, China, Iran, and Egypt. Much of the turquoise found today is either stabilized or treated with waxes and resins to enhance its color and durability, especially for jewelry use.
Tanzanite
Tanzanite is a trigonal mineral and a variety of columbite, which is a niobium-tantalum bearing mineral. It forms under high-pressure metamorphic conditions, typically in alkaline rock formations. Tanzanite is found exclusively in Tanzania, specifically in the Merelani Hills near Mount Kilimanjaro.
The gemstone’s violet-blue color is due to the presence of violet color centers, which are created when the mineral is exposed to heat and radiation. Most tanzanite is heat-treated to enhance its color, as raw crystals often exhibit a brownish or grayish hue.
Zircon
Zircon is a zirconium silicate that occurs in a wide range of colors, including blue, red, brown, and colorless. The blue zircon most commonly associated with December is typically heat-treated to achieve its bright blue color.
Zircon forms in igneous and metamorphic rocks, and it is often found in beach sands and alluvial deposits. Major sources of zircon include Sri Lanka, Cambodia, Australia, and India. Due to its high refractive index and dispersion, zircon is known for its sparkling brilliance, making it a popular alternative to diamonds and other precious stones.
Blue Topaz
Blue topaz is a silicate mineral and a member of the topaz family. It forms in pegmatite rocks, which are igneous rocks that cool slowly, allowing large crystals to develop. Natural blue topaz is extremely rare, and most of the blue topaz available in the market is irradiated and heat-treated to achieve its icy blue color.
Blue topaz is found in various parts of the world, including Brazil, Myanmar, Russia, and the United States. It is one of the most affordable and durable December birthstones, with a Mohs hardness of 8, making it suitable for daily wear in rings, necklaces, and bracelets.
Gemological Properties of December Birthstones
| Property | Turquoise | Tanzanite | Zircon | Blue Topaz |
|---|---|---|---|---|
| Color | Sky blue to greenish blue | Violet-blue (color-shifting) | Bright blue | Pale to deep blue |
| Chemical Formula | CuAl₆(PO₄)₄(OH)₈·4H₂O | (Ca,Na)₂(Zr,Ti,Nb)₂(SiO₄)₂O | ZrSiO₄ | Al₂SiO₄(F,OH)₂ |
| Hardness (Mohs) | 5–6 | 6–7 | 6.5–7.5 | 8 |
| Cleavage | Perfect in one direction | Indistinct | Poor to none | None |
| Refractive Index | 1.61–1.65 | 1.694–1.701 | 1.92–2.01 | 1.62–1.64 |
| Luster | Waxy to vitreous | Vitreous | Vitreous | Vitreous |
| Transparency | Opaque to translucent | Transparent to translucent | Transparent to translucent | Transparent |
| Treatment | Stabilization common | Heat treatment common | Heat treatment common | Irradiation and heat treatment common |
| Best for | Earrings, pendants, beads | Occasional rings, earrings, pendants | Earrings, pendants, protected rings | Daily wear rings, all jewelry |
These properties highlight the differences in durability and care requirements among the December birthstones. Turquoise and tanzanite, for instance, are softer and more fragile, requiring gentle handling and protective settings in jewelry. Zircon and blue topaz, on the other hand, are more durable, making them better choices for daily wear.
Symbolism and Metaphysical Beliefs
The December birthstones are not only admired for their beauty but also for the symbolic meanings they carry across different cultures and traditions.
Turquoise
In many ancient cultures, turquoise was considered a stone of protection and healing. It was often worn as a talisman to ward off evil spirits and promote mental clarity and emotional stability. In Native American traditions, turquoise is seen as a spiritual stone, used in ceremonial jewelry and ritual objects. It is believed to connect the earth and the heavens, acting as a bridge between the physical and spiritual worlds.
Tanzanite
Tanzanite is associated with transformation, intuition, and emotional balance. It is often used in spiritual practices to enhance inner peace and emotional healing. The stone’s violet-blue color is said to resonate with the third eye and throat chakras, promoting clarity of thought and expression.
Zircon
Zircon is believed to enhance memory, wisdom, and focus. It is also associated with good fortune and protection from negative energies. In some cultures, zircon is used to enhance psychic abilities and encourage spiritual growth. Its brilliance and fire are said to reflect the inner spark of the wearer.
Blue Topaz
Blue topaz is linked to calmness, courage, and clarity. It is often used to relieve stress and anxiety, helping the wearer to maintain a sense of balance and composure. In some traditions, blue topaz is also associated with love and friendship, making it a popular choice for engagement rings and anniversary gifts.
Care and Maintenance of December Birthstone Jewelry
Proper care is essential to maintaining the beauty and longevity of December birthstone jewelry. Here are some guidelines for each gemstone:
Turquoise
- Avoid exposure to chemicals, heat, and moisture, as these can cause the stone to fade or become brittle.
- Clean gently with a soft cloth and lukewarm soapy water.
- Store separately to prevent scratches from harder gemstones.
Tanzanite
- Avoid sharp impacts, as tanzanite has natural cleavage planes that can chip or crack under pressure.
- Clean with warm, soapy water and a soft brush.
- Avoid ultrasonic and steam cleaners, which can damage the stone.
Zircon
- Protect the edges of zircon jewelry, as the stone can be brittle at the corners.
- Clean with mild soapy water and a soft brush.
- Avoid steam and ultrasonic cleaners, which can weaken the stone.
Blue Topaz
- Topaz is durable, with a Mohs hardness of 8, making it suitable for daily wear.
- However, it has a natural cleavage, so it can chip if struck sharply.
- Clean with warm, soapy water and a soft brush.
- Avoid harsh chemicals and ultrasonic cleaners, which can damage the stone’s surface.
Conclusion
December is a month of celebration, and its association with multiple blue gemstones reflects the rich diversity of colors, meanings, and histories that make each birthstone unique. Turquoise, tanzanite, zircon, and blue topaz each bring their own aesthetic appeal and symbolic value, offering a wide range of options for jewelry lovers and collectors.
While aquamarine is often marketed as a December birthstone, it is actually the March birthstone, and its inclusion in December-themed jewelry is more of a marketing choice than a traditional one. Understanding the true December birthstones allows for more informed purchasing and appreciation of these beautiful gems.
Whether you're drawn to the soft blues of turquoise, the vibrant violet of tanzanite, the sparkling brilliance of zircon, or the icy clarity of blue topaz, there is a December birthstone to suit every style and preference. With proper care and understanding, these gemstones can be cherished for generations, carrying both their beauty and their meaning forward in time.