If you were born on December 15th, you are among the lucky ones who share a birthstone month with a rich selection of gemstones. December is unique in that it is associated with four official birthstones: turquoise, blue topaz, zircon, and tanzanite. These gemstones have been cherished across centuries for their beauty, symbolism, and unique properties. For those born in the middle of December, including December 15th, the most commonly referenced and historically significant birthstones are turquoise, blue zircon, and tanzanite.
This article explores the geological, historical, and cultural significance of these three gemstones, their spiritual meanings, care instructions, and their place in modern gemology and jewelry design. Drawing from authoritative and historical sources, we will uncover what makes these stones not only beautiful, but deeply meaningful to those who wear them.
The Significance of December 15th and the December Birthstones
December 15th falls in the heart of winter, a time often associated with reflection, protection, and transformation. Each of the December birthstones—turquoise, zircon, and tanzanite—resonates with these themes, reflecting different aspects of the season and the month’s energy.
In ancient times, the December birthstone was often associated with protection, clarity, and emotional balance. These stones were believed to offer not just physical protection but also emotional and spiritual support. As we explore each of these gems, we’ll see how their unique properties and histories make them fitting symbols for the month of December.
History and Lore: Ancient Roots of the December Birthstones
Turquoise: The Stone of Ancient Royalty and Protection
Turquoise is one of the oldest known gemstones in human history. Its use dates back over 5,000 years, with evidence of its presence in ancient Egyptian, Persian, and Native American cultures. In ancient Egypt, turquoise was revered as a sacred stone associated with the gods and was often inlaid in royal jewelry and amulets. It was believed to bring protection, prosperity, and spiritual clarity.
In Persia and Central Asia, turquoise was used in traditional jewelry, talismans, and even in the decoration of weapons and armor, signifying both strength and divine favor. Native American tribes, particularly the Navajo and Zuni, used turquoise in their ceremonial jewelry and believed it to be a mediator between the earth and the heavens.
Turquoise was also considered a December birthstone long before the modern era, and it continues to hold a place of honor among those born in the month. In ancient times, it was associated with Sagittarius, one of the zodiac signs linked to December.
Zircon: The "Hidden" December Birthstone
Zircon, particularly blue zircon, became a recognized December birthstone in 1952, replacing lapis lazuli. Before this, lapis lazuli had been a popular birthstone for December, especially among European royalty and artists. Zircon is a gemstone with a long history, though its use in jewelry is more modern compared to turquoise.
Zircon was known in ancient times but was often confused with hyacinth, another gemstone. It is a silicate mineral that occurs in a wide variety of colors, including blue, yellow, green, and brown. The blue variety, known as starlight blue zircon, is the most common December birthstone and is prized for its vibrant color and brilliance.
Zircon was believed to bring joy, emotional balance, and clarity of thought. It has a quiet vibrational energy that resonates well with those seeking inner peace and understanding.
Tanzanite: The Modern Discovery of December
Tanzanite is the youngest of the December birthstones, having been officially recognized as such in 2002. It was first discovered in 1967 in Tanzania, near the base of Mount Kilimanjaro, and was named after the country of its origin. Tanzanite is a trigonal mineral that is a form of cushion or violet-colored zoisite.
Tanzanite is unique because it is only found in Tanzania, making it one of the rarest gemstones in the world. It is known for its violet-blue color, which can vary depending on the lighting conditions. Tanzanite is also known for its pleochroism, meaning it displays different colors when viewed from different angles.
Symbolically, tanzanite is associated with transformation, spiritual awakening, and emotional healing. It is believed to help the wearer connect with their heart chakra, promoting emotional openness and compassion.
Geological Formation and Sources
Understanding how these gemstones are formed and where they are found helps us appreciate their rarity and value.
Turquoise: A Product of Nature’s Alchemy
Turquoise is a phosphate mineral, specifically a trigonal mineral composed of copper, aluminum, and phosphorus. It is formed when acidic, copper-rich water interacts with aluminum and phosphorus in the soil. This process typically occurs in arid regions, where weathered volcanic rock and sedimentary rock create the perfect conditions for turquoise formation.
The most important sources of turquoise are Iran, China, the United States (particularly Nevada and Arizona), Egypt, and Mexico. Turquoise from Iran and Nevada is especially prized for its deep blue color and minimal matrix (the dark webbing that appears in the stone).
Turquoise has a Mohs hardness of 5 to 6, making it relatively soft and porous. It is easily damaged by chemicals, oils, and moisture, which is why it requires careful handling and storage.
Zircon: A Diverse and Durable Gemstone
Zircon is a zirconium silicate mineral that occurs in a wide range of colors. The blue zircon used as a December birthstone is not naturally blue, but is heated to produce its vibrant color. This process is stable and does not affect the stone’s durability.
Zircon has a Mohs hardness of 6 to 7.5, depending on the variety, making it more durable than turquoise. It is often found in granitic rocks and metamorphic rocks, particularly in Australia, Brazil, India, and Cambodia.
Blue zircon is especially popular in December jewelry due to its brilliance and affordability. It is also known for its high refractive index, which gives it a sparkling, glass-like appearance.
Tanzanite: A Unique Geological Phenomenon
Tanzanite is a trigonal mineral that is a variety of zoisite, a calcium aluminum silicate. It is only found in Tanzania, in a narrow region near the base of Mount Kilimanjaro. This geographical exclusivity makes tanzanite one of the rarest gemstones in the world.
The formation of tanzanite requires very specific geological conditions, including high pressure and temperature, as well as the presence of vanadium, which gives the stone its violet-blue color. Tanzanite has a Mohs hardness of 6 to 7, making it relatively durable, though it is susceptible to heat and light over time.
Tanzanite is known for its pleochroism, meaning it displays different colors when viewed from different angles. This property makes each tanzanite stone unique and fascinating to study.
Gemological Properties
Each of these gemstones has distinct physical and optical properties that make them stand out in the world of gemology.
Turquoise
- Chemical Formula: CuAl₆(PO₄)₄(OH)₈·4H₂O
- Hardness (Mohs): 5 to 6
- Luster: Waxy to greasy
- Color: Ranges from greenish-blue to robin’s egg blue, often with matrix patterns
- Specific Gravity: 2.6 to 2.8
- Refractive Index: 1.61 to 1.65
- Transparency: Opaque to slightly translucent
Turquoise is a soft and porous gemstone that is easily damaged by chemicals and moisture. It is often treated with resin or oil to enhance its color and durability.
Zircon
- Chemical Formula: ZrSiO₄
- Hardness (Mohs): 6 to 7.5
- Luster: Vitreous to subadamantine
- Color: Available in blue, yellow, green, brown, and colorless, with blue zircon being the most common December birthstone
- Specific Gravity: 4.6 to 4.7
- Refractive Index: 1.92 to 2.01
- Transparency: Transparent to translucent
Zircon is a highly refractive gemstone, meaning it bends light very effectively, giving it a sparkling appearance. Blue zircon is typically heat-treated to produce its vibrant color.
Tanzanite
- Chemical Formula: Ca₂Al₃(SiO₄)(OH)₂
- Hardness (Mohs): 6 to 7
- Luster: Vitreous to pearly
- Color: Violet-blue to purplish-blue, with pleochroism
- Specific Gravity: 3.1 to 3.4
- Refractive Index: 1.69 to 1.70
- Transparency: Transparent to translucent
Tanzanite is known for its unique color and pleochroism, which means it displays different colors when viewed from different angles. This property is uncommon in other gemstones.
Symbolism and Metaphysical Beliefs
Each of these gemstones carries deep symbolic meaning and is associated with various spiritual and emotional properties.
Turquoise: Protection, Clarity, and Intuition
In ancient times, turquoise was considered a stone of protection, often used in amulets and talismans. It was believed to ward off negative energy, enhance intuition, and promote emotional balance. In Native American traditions, turquoise was associated with healing, fertility, and spiritual communication.
Modern metaphysical beliefs suggest that turquoise promotes calmness, reduces stress, and enhances creativity. It is also believed to open the throat chakra, helping the wearer express their thoughts and emotions more clearly.
Zircon: Emotional Balance and Spiritual Clarity
Zircon is a quiet but powerful gemstone that is believed to promote emotional balance and spiritual clarity. It is associated with joy, inner peace, and the ability to navigate complex situations with ease.
Zircon is also believed to align the body’s energy meridians, helping the wearer connect with higher spiritual sources. It is particularly useful for meditation and spiritual exploration, as it is thought to enhance one’s ability to receive divine guidance.
Tanzanite: Transformation and Emotional Healing
Tanzanite is a stone of transformation and emotional healing. It is believed to help the wearer release old emotional patterns and embrace new beginnings. It is associated with the heart chakra, promoting emotional openness and compassion.
Tanzanite is also believed to enhance spiritual awareness and intuition, making it a valuable stone for those on a spiritual path. It is often used in energy healing and chakra balancing, as it is thought to help the wearer connect with their inner wisdom and higher self.
Care and Cleaning
Proper care is essential to preserve the beauty and integrity of these gemstones. Each stone has unique care requirements based on its hardness, porosity, and sensitivity to chemicals and light.
Turquoise
Turquoise is a soft and porous gemstone that is easily damaged by chemicals, oils, and moisture. To care for turquoise jewelry:
- Avoid exposure to chemicals, such as perfumes, lotions, and cleaning agents.
- Store in a dry, cool place, preferably in a jewelry pouch or box.
- Avoid prolonged exposure to sunlight, as this can fade the color.
- Clean with a soft cloth and mild soap, avoiding abrasive materials.
Zircon
Zircon is more durable than turquoise, but it still requires careful handling to maintain its brilliance and color.
- Avoid exposure to high heat, as this can alter the color of zircon.
- Store zircon away from other gemstones, as it can be scratched.
- Clean with warm, soapy water and a soft cloth.
- Avoid ultrasonic cleaners, as they can damage the stone’s internal structure.
Tanzanite
Tanzanite is a relatively durable gemstone, but it is susceptible to heat and light over time.
- Avoid prolonged exposure to sunlight, as this can fade the color.
- Store tanzanite in a cool, dark place.
- Clean with a soft cloth and mild soap.
- Avoid abrasive materials and ultrasonic cleaners.
Conclusion
The December 15th birthstone is a symbol of protection, emotional balance, and transformation, embodied by the gemstones turquoise, zircon, and tanzanite. These stones have rich histories, deep cultural significance, and unique gemological properties that make them valuable both as jewelry and as symbols of personal and spiritual growth.
Whether you choose turquoise for its ancient wisdom and protective energy, zircon for its emotional clarity and spiritual insight, or tanzanite for its transformative power and emotional healing, these gemstones offer a meaningful connection to the energies of December.
By understanding their history, properties, and care requirements, you can cherish and preserve these beautiful gemstones for years to come. As you wear or gift these stones, you carry with you a piece of December’s magic, beauty, and timeless wisdom.