December 15th is a date associated with three distinct yet similarly captivating gemstones: Tanzanite, Turquoise, and Zircon. Together, these birthstones embody the rich symbolism, historical significance, and geological diversity that define the world of gemology. While each gemstone has its own unique properties and allure, they are united by their striking blue hues and their roles as December birthstones. This article delves into the history, properties, and cultural significance of these three gems, providing a comprehensive overview for gemstone enthusiasts, jewelry buyers, and students of gemology alike.
Introduction
December 15th birthstones include Tanzanite, Turquoise, and Zircon—each celebrated for its distinct characteristics and associations. These gemstones are not only visually stunning but also carry deep historical and cultural meanings. Tanzanite, discovered relatively recently in the 20th century, is known for its intense blue and violet hues. Turquoise, a gem with a long and storied history, has been cherished by ancient civilizations for its protective and spiritual properties. Zircon, particularly in its blue form, is prized for its brilliance and clarity. Together, these stones represent the diversity and richness of December’s birthstone tradition.
This article explores the origins, gemological properties, cultural significance, and care requirements of these three birthstones. By examining each gemstone in detail, readers can gain a deeper appreciation for their unique qualities and the reasons they have been cherished for generations.
History and Lore
The use of gemstones as symbols of identity, protection, and spiritual power has a long history. For December 15th, the trio of Tanzanite, Turquoise, and Zircon each carries its own historical narrative, rooted in different cultures and eras.
Turquoise: An Ancient Gemstone
Turquoise is among the oldest known gemstones, with evidence of its use dating back thousands of years. It has been found in archaeological sites across the Middle East, North Africa, and the Americas. Ancient Egyptians used turquoise for jewelry and amulets, believing it to bring protection and good fortune. In Native American cultures, particularly among the Navajo and Hopi tribes, turquoise was considered sacred and was often used in ceremonial jewelry and talismans. The gemstone’s blue-green color was associated with the sky and water, making it a symbol of life and vitality.
In medieval Europe, turquoise was also highly valued. It was often inlaid in gold and silver to create intricate jewelry pieces. The gemstone was believed to have protective properties, especially for warriors and travelers. These beliefs persisted into the Renaissance and beyond, with turquoise continuing to be a popular choice for both decorative and symbolic jewelry.
Tanzanite: A Modern Discovery
Unlike Turquoise, Tanzanite is a relatively recent discovery in the world of gemology. It was first identified in 1967 in the Merelani Hills of Tanzania, near the base of Mount Kilimanjaro. Tanzanite is a variety of the mineral zoisite, distinguished by its intense blue and violet hues. The gemstone was named after Tanzania, the only country where it is found in nature.
The discovery of Tanzanite was significant not only because of its beauty but also because of its rarity. The gemstone’s limited geographic source and the unique geological conditions required for its formation make it a highly sought-after gem in the jewelry industry. Tanzanite quickly gained popularity in the 1970s and 1980s, becoming a symbol of modern elegance and sophistication.
Zircon: A Timeless Stone
Zircon has been known and used for centuries, with examples of zircon jewelry found in ancient civilizations such as Mesopotamia, Egypt, and the Indus Valley. The gemstone was particularly popular in the Roman Empire, where it was often referred to as “hyacinth.” Zircon was also used in medieval Europe and was sometimes confused with diamonds due to its brilliance and refractive qualities.
In the modern era, Zircon has been recognized for its diverse color range, with the blue variety being especially popular as a December birthstone. Blue Zircon is created through heat treatment, which enhances its natural color and clarity. This treatment is stable and permanent, making blue Zircon a durable and affordable option for jewelry.
Geological Formation and Sources
Understanding the geological origins of these gemstones provides insight into their rarity, beauty, and the conditions under which they form. Each of the December 15th birthstones—Tanzanite, Turquoise, and Zircon—has a unique formation process and geographic distribution.
Tanzanite: A Rare and Exclusive Gem
Tanzanite is a variety of the mineral zoisite, with the chemical formula Ca₂Al₃(SiO₄)(Si₂O₇)O(OH). It is formed under high-pressure, high-temperature conditions, typically in metamorphic rocks. The Merelani Hills in Tanzania are the only known source of Tanzanite in nature. The gemstone is found in a small area of about 5 square kilometers, which contributes to its rarity.
The unique blue and violet coloration of Tanzanite is due to the presence of vanadium and the gemstone’s exposure to natural radiation. The intensity of the color can vary depending on the cutting and polishing techniques used. Tanzanite is typically found in rough form as irregular, massive crystals or as fragments embedded in surrounding rock. It is then cut and polished to enhance its color and clarity.
Turquoise: A Hydrated Phosphate Mineral
Turquoise is a hydrated phosphate mineral with the chemical formula CuAl₆(PO₄)₄(OH)₈·4H₂O. It forms in arid environments, typically in the oxidation zones of copper deposits. The gemstone is created when water percolates through the ground, dissolving copper and aluminum compounds and depositing them in the rock over time.
Major sources of turquoise include the United States (particularly Arizona, New Mexico, and Nevada), China, Iran, and Egypt. Each location produces turquoise with distinct characteristics, such as color, matrix patterns, and hardness. The most highly prized turquoise is typically found in the American Southwest, where it has been used for centuries in Native American jewelry.
Turquoise is a relatively soft gemstone, with a hardness of 5 to 6 on the Mohs scale. It is also porous, which means it can absorb oils, lotions, and other substances. This property requires careful handling and storage to prevent damage or discoloration.
Zircon: A Durable and Diverse Gemstone
Zircon is a silicate mineral with the chemical formula ZrSiO₄. It is found in a wide range of colors, including colorless, yellow, red, green, and blue. The blue variety of Zircon is the most commonly recognized as a December birthstone. This coloration is achieved through heat treatment, which removes impurities and enhances the gemstone’s natural color.
Zircon is typically found in metamorphic and igneous rocks, as well as in alluvial deposits. Major sources of zircon include Sri Lanka, Myanmar, Cambodia, and Brazil. The gemstone is known for its high refractive index and dispersion, which give it a brilliant, diamond-like appearance. Zircon is also one of the oldest minerals on Earth, with some zircon crystals dating back over 4 billion years.
Zircon has a hardness of 6.5 to 7.5 on the Mohs scale, making it relatively durable for use in jewelry. However, it is sensitive to heat and radiation, so care must be taken during cutting and polishing to avoid damage.
Gemological Properties
To appreciate the beauty and value of a gemstone, it is essential to understand its physical and optical properties. Tanzanite, Turquoise, and Zircon each have unique characteristics that define their appearance, durability, and suitability for jewelry.
Tanzanite: A Radiant Blue Gemstone
Tanzanite is known for its striking blue and violet coloration, which is enhanced through heat treatment. The gemstone has a hardness of 6 to 6.5 on the Mohs scale, which makes it relatively durable but still susceptible to scratches and abrasions. Tanzanite has a refractive index of 1.69 to 1.70 and a specific gravity of 3.1 to 3.4.
One of the most notable properties of Tanzanite is its pleochroism, meaning it displays different colors when viewed from different angles. This effect is particularly pronounced in Tanzanite, where the gemstone can appear blue, violet, or even brown depending on the viewing angle. Tanzanite is also slightly radioactive due to the presence of trace amounts of uranium and thorium in its structure.
The gemstone is typically cut into oval, cushion, or emerald shapes to maximize its color and brilliance. Tanzanite is often set in gold or silver, and it is popular in rings, pendants, and earrings.
Turquoise: A Soft and Porous Gemstone
Turquoise is an opaque gemstone with a hardness of 5 to 6 on the Mohs scale. It has a refractive index of 1.61 to 1.65 and a specific gravity of 2.6 to 2.8. The gemstone is known for its distinctive blue to greenish-blue color, which is caused by the presence of copper and aluminum compounds. Turquoise also often contains veins or patterns of black or brown, known as matrix, which add to its unique appearance.
Turquoise is a porous gemstone, which means it can absorb oils, lotions, and other substances. This property makes it sensitive to cleaning agents and requires careful handling. Turquoise is typically stabilized or treated with resin to enhance its durability and reduce porosity. Stabilized turquoise is more suitable for jewelry, while natural, untreated turquoise is best preserved in a controlled environment.
The gemstone is often cut into cabochons to enhance its color and to avoid the risk of scratches. Turquoise is commonly set in silver, and it is used in a wide range of jewelry, including rings, pendants, and bracelets.
Zircon: A Brilliant and Durable Gemstone
Zircon is a silicate mineral with a hardness of 6.5 to 7.5 on the Mohs scale. It has a high refractive index of 1.92 to 2.00 and a high dispersion, which gives it a brilliant, fire-like appearance. Zircon is found in a wide range of colors, but the blue variety is the most commonly recognized as a December birthstone.
Blue Zircon is created through heat treatment, which removes impurities and enhances the gemstone’s natural color. The color change is stable and permanent, making blue Zircon a popular choice for jewelry. Zircon is also known for its high refractive index and dispersion, which give it a brilliant, diamond-like appearance.
Zircon is typically cut into brilliant or modified brilliant shapes to maximize its fire and brilliance. The gemstone is often set in silver or gold and is used in rings, pendants, and earrings. Zircon is relatively affordable compared to other gemstones of similar beauty and brilliance.
Symbolism and Metaphysical Beliefs
Gemstones have long been associated with symbolic meanings and metaphysical properties. These beliefs vary across cultures and time periods but often reflect the gemstone’s physical properties and aesthetic appeal. Tanzanite, Turquoise, and Zircon each carry unique symbolic and metaphysical associations that have been passed down through generations.
Tanzanite: A Stone of Transformation
Tanzanite is often associated with transformation, intuition, and spiritual growth. The gemstone is believed to enhance the wearer’s ability to see beyond the surface and to understand the deeper truths of life. Tanzanite is also associated with the throat and third eye chakras, making it a popular choice for those seeking to enhance their communication and spiritual insight.
In modern metaphysical practices, Tanzanite is believed to promote emotional healing and to help individuals release fear and anxiety. The gemstone is also thought to encourage creativity and self-expression, making it a valuable tool for artists and writers.
Turquoise: A Stone of Protection and Clarity
Turquoise has been used for centuries as a protective and healing gemstone. In ancient cultures, it was believed to offer protection from negative energies and to promote good health and vitality. The gemstone was also associated with clarity of thought and emotional stability, making it a popular choice for those seeking to enhance their intuition and decision-making abilities.
In modern times, Turquoise is still valued for its protective and calming properties. It is believed to help individuals maintain balance and harmony in their lives, especially during times of stress or uncertainty. Turquoise is also associated with the throat and heart chakras, making it a popular choice for those seeking to enhance their communication and emotional well-being.
Zircon: A Stone of Clarity and Confidence
Zircon, particularly in its blue form, is associated with clarity, confidence, and spiritual awakening. The gemstone is believed to help individuals see the truth and to make clear, rational decisions. Zircon is also associated with the heart and crown chakras, making it a popular choice for those seeking to enhance their emotional and spiritual connection.
In modern metaphysical practices, Zircon is believed to promote self-confidence and to help individuals overcome self-doubt and fear. The gemstone is also thought to encourage personal growth and transformation, making it a valuable tool for those seeking to enhance their self-esteem and assertiveness.
Care and Cleaning
Proper care and cleaning are essential for maintaining the beauty and longevity of gemstone jewelry. Each of the December 15th birthstones—Tanzanite, Turquoise, and Zircon—has specific care requirements based on its physical properties and vulnerabilities.
Tanzanite: Gentle Handling and Protection
Tanzanite is a relatively soft gemstone with a hardness of 6 to 6.5 on the Mohs scale. It is also slightly radioactive and can be sensitive to heat and light. To care for Tanzanite jewelry, it is important to avoid exposure to harsh chemicals and abrasive materials. The gemstone should be cleaned with a soft, lint-free cloth and warm, soapy water. A soft-bristled brush can be used to gently remove dirt and debris.
Tanzanite should be stored in a separate compartment or pouch to prevent scratches from harder gemstones. It is also best to remove Tanzanite jewelry before engaging in activities that may cause physical damage or exposure to chemicals.
Turquoise: Avoiding Chemicals and Moisture
Turquoise is a porous gemstone that can absorb oils, lotions, and other substances. It is also sensitive to chemicals and moisture, which can cause discoloration and degradation. To care for Turquoise jewelry, it is important to avoid exposure to harsh cleaning agents, perfumes, and lotions. The gemstone should be cleaned with a soft, lint-free cloth and warm, soapy water. A soft-bristled brush can be used to gently remove dirt and debris.
Turquoise should be stored in a dry, cool place to prevent moisture-related damage. It is also best to remove Turquoise jewelry before engaging in activities that may cause physical damage or exposure to chemicals.
Zircon: Resisting Heat and Radiation
Zircon is a relatively durable gemstone with a hardness of 6.5 to 7.5 on the Mohs scale. However, it is sensitive to heat and radiation, which can cause damage to the gemstone. To care for Zircon jewelry, it is important to avoid exposure to high temperatures and direct sunlight. The gemstone should be cleaned with a soft, lint-free cloth and warm, soapy water. A soft-bristled brush can be used to gently remove dirt and debris.
Zircon should be stored in a separate compartment or pouch to prevent scratches from harder gemstones. It is also best to remove Zircon jewelry before engaging in activities that may cause physical damage or exposure to heat.
Conclusion
December 15th is associated with three remarkable gemstones: Tanzanite, Turquoise, and Zircon. Each of these stones carries its own unique history, gemological properties, and symbolic significance. Tanzanite, with its striking blue and violet hues, is a rare and modern gemstone that is associated with transformation and spiritual growth. Turquoise, an ancient gemstone with a long and storied history, is valued for its protective and calming properties. Zircon, particularly in its blue form, is prized for its brilliance and clarity, making it a popular choice for jewelry.
Understanding the origins, properties, and symbolism of these gemstones provides a deeper appreciation for their beauty and significance. Whether chosen for their aesthetic appeal, historical value, or metaphysical properties, these gemstones continue to be cherished by gemstone enthusiasts and jewelry lovers around the world.