December 19th is a date rich in gemological tradition, marked by the association with three distinct and meaningful birthstones: tanzanite, turquoise, and zircon. Each of these gemstones carries a unique set of physical properties, historical significance, and metaphysical attributes that contribute to their enduring appeal in the world of jewelry and spiritual practices.
This article explores the historical evolution of these birthstones, their geological origins, gemological properties, and the cultural meanings they have acquired over centuries. We also discuss practical care and maintenance tips to help preserve their beauty and value.
Historical Evolution of December Birthstones
The tradition of assigning gemstones to months of the year is an ancient one, with its roots stretching back to biblical times. The earliest known references to birthstones appear in the Book of Exodus, where 12 gemstones were listed on the breastplate of the High Priest Aaron, representing the 12 tribes of Israel. However, these early lists did not assign gemstones to months but rather to tribes or people.
The modern concept of birthstones began to take shape during the 19th and 20th centuries. In 1870, Tiffany & Co. published the first American version of a birthstone list, which included turquoise for December. This marked the beginning of the modern birthstone tradition in the Western world. In 1912, the National Association of Jewellers (now the American Gem Trade Association) expanded the list to include lapis lazuli as an alternative to turquoise.
A significant development occurred in 1952, when zircon was officially added to the list of December birthstones. Finally, in 2002, tanzanite—a relatively modern gemstone—was introduced as the third official December birthstone. The inclusion of multiple stones for December reflects a desire to offer a broader range of choices in terms of color, price, and personal meaning.
For those born on December 19th, the selection of tanzanite, turquoise, and zircon is particularly significant, as these stones represent the rich and diverse heritage of December’s gemstone tradition.
Tanzanite: A Modern Marvel
Origin and Discovery
Tanzanite is the youngest of the modern birthstones, first discovered in 1967 near the base of Mount Kilimanjaro in Tanzania. The gemstone was initially found as a violet-colored rock, but it was soon realized that it could be heat-treated to reveal its characteristic blue to violet hues. This transformation gave the gemstone its name—Tanzanite, a portmanteau of Tanzania and the suffix -ite, commonly used for minerals.
Geological Formation and Sources
Tanzanite is a type of columbite, a mineral that forms in metamorphic rocks under high heat and pressure. It is found almost exclusively in the Merelani Hills of northern Tanzania, making it one of the rarest gemstones in the world. The gemstone’s blue to violet coloration is due to the presence of trivalent iron (Fe³⁺) and trivalent chromium (Cr³⁺) in its crystal structure.
Gemological Properties
Tanzanite has the following key gemological properties:
| Property | Value |
|---|---|
| Chemical Formula | Ca₂Al₃(AlSiO₄)₃(OH)₄ |
| Hardness (Mohs) | 6 to 7 |
| Refractive Index | 1.694 to 1.706 |
| Specific Gravity | 3.14 to 3.35 |
| Color | Blue to violet (often with a pleochroic effect) |
| Cleavage | Poor to moderate |
| Luster | Vitreous |
| Transparency | Transparent to translucent |
Tanzanite is pleochroic, meaning it exhibits different colors when viewed from different angles. This unique property gives it a dynamic and captivating appearance, especially under natural light.
Symbolism and Metaphysical Beliefs
Tanzanite is often associated with spiritual growth, emotional balance, and success. It is believed to enhance intuition, compassion, and inner strength, making it a popular stone for meditation and spiritual practices. Some sources also suggest that tanzanite can help in resolving conflicts and promoting harmony in relationships.
Care and Cleaning
Tanzanite is relatively soft and sensitive to damage. It should be cleaned using warm water and mild soap, with a soft cloth or soft-bristled brush. It is important to store tanzanite separately from harder gemstones to avoid scratches. While it is generally not sensitive to light or heat, it should be kept away from chemicals or harsh cleaning agents.
Turquoise: A Stone of Protection and Healing
Historical Significance
Turquoise has been revered for thousands of years by various ancient civilizations, including the Egyptians, Native Americans, and Persians. It was often used in amulets and talismans, believed to offer protection, good fortune, and emotional healing. The stone’s vibrant blue to greenish-blue color has made it a symbol of serenity, wisdom, and spiritual clarity.
In ancient Egypt, turquoise was considered a sacred stone, often used in jewelry and funerary items to protect the deceased in the afterlife. Native American tribes, particularly the Navajo and Zuni, used turquoise in ceremonial jewelry and carvings, believing it to bring balance and harmony.
Geological Formation and Sources
Turquoise is a phosphate mineral composed of copper and aluminum, with a chemical formula of CuAl₆(PO₄)₄(OH)₈·4H₂O. It forms in low-temperature hydrothermal environments, typically in cavities and veins of volcanic rock. The most famous sources of turquoise include:
- Iran (Persia) – Known for producing the finest quality turquoise in history
- United States – Particularly Arizona and Nevada, which are major sources of turquoise today
- China, Egypt, and Mexico – Also known for producing high-quality turquoise
Turquoise is often treated with resin or oil to enhance its color and stability, especially in lower-grade stones.
Gemological Properties
Turquoise has the following key gemological properties:
| Property | Value |
|---|---|
| Chemical Formula | CuAl₆(PO₄)₄(OH)₈·4H₂O |
| Hardness (Mohs) | 5 to 6 |
| Refractive Index | 1.61 to 1.65 |
| Specific Gravity | 2.6 to 2.8 |
| Color | Blue to greenish-blue (with white or black matrix patterns) |
| Cleavage | None |
| Luster | Waxy to greasy |
| Transparency | Opaque |
| Treatments | Stabilization with resin or oil (common in lower-grade stones) |
Turquoise is relatively soft and porous, making it susceptible to damage from chemicals, heat, and moisture.
Symbolism and Metaphysical Beliefs
Turquoise is one of the most spiritually significant gemstones in history. It is associated with healing, protection, and wisdom, and is often used in meditation and spiritual practices to promote emotional balance and communication. Some sources also suggest that turquoise can strengthen the immune system, aid in detoxification, and relieve stress or anxiety.
Care and Cleaning
Turquoise requires gentle care due to its soft and porous nature. It should be cleaned using warm water and mild soap, and avoided contact with chemicals, harsh cleaning agents, and prolonged exposure to heat or light. It is best to store turquoise separately from other gemstones to prevent scratches.
Zircon: A Sparkling Ancient Gem
Historical Significance
Zircon is one of the oldest known minerals on Earth, with some zircon crystals dated to over 4.4 billion years old. It has been used in jewelry for thousands of years, particularly in ancient Egypt and Mesopotamia, where it was valued for its brilliance and fire. The name "zircon" is derived from the Persian word "zargun", meaning "gold-colored", although zircon can occur in a wide range of colors, including colorless, yellow-gold, red, green, and blue.
Geological Formation and Sources
Zircon is a zirconium silicate mineral that forms in igneous and metamorphic rocks. It is found in various parts of the world, including:
- Australia – Known for producing colorless and blue zircons
- Brazil – A major source of high-quality zircons
- India, Thailand, and Cambodia – Also important sources of zircon
Zircon is often heat-treated to enhance its color, particularly to produce the blue zircon that is most commonly associated with the December birthstone tradition.
Gemological Properties
Zircon has the following key gemological properties:
| Property | Value |
|---|---|
| Chemical Formula | ZrSiO₄ |
| Hardness (Mohs) | 6 to 7.5 |
| Refractive Index | 1.92 to 2.01 |
| Specific Gravity | 4.6 to 4.7 |
| Color | Colorless, yellow-gold, red, green, blue |
| Cleavage | None |
| Luster | Vitreous |
| Transparency | Transparent to translucent |
| Treatments | Heat treatment (common for enhancing color) |
Zircon is known for its high refractive index and dispersion, which gives it a sparkling, fire-like brilliance similar to diamond.
Symbolism and Metaphysical Beliefs
Zircon is associated with intuition, creativity, and motivation. It is believed to enhance mental clarity, emotional stability, and spiritual insight, making it a popular stone for meditation and spiritual practices. Some sources also suggest that zircon can promote restful sleep, attract wealth, and increase wisdom and understanding.
Care and Cleaning
Zircon is generally hard and durable, making it easier to care for compared to tanzanite and turquoise. It can be cleaned with warm water and mild soap, using a soft cloth or brush. Zircon should be stored separately from harder gemstones to avoid scratches, but it is generally not sensitive to light or heat.
Comparative Analysis of December 19th Birthstones
| Property | Tanzanite | Turquoise | Zircon |
|---|---|---|---|
| Chemical Formula | Ca₂Al₃(AlSiO₄)₃(OH)₄ | CuAl₆(PO₄)₄(OH)₈·4H₂O | ZrSiO₄ |
| Hardness (Mohs) | 6 to 7 | 5 to 6 | 6 to 7.5 |
| Refractive Index | 1.694 to 1.706 | 1.61 to 1.65 | 1.92 to 2.01 |
| Specific Gravity | 3.14 to 3.35 | 2.6 to 2.8 | 4.6 to 4.7 |
| Color | Blue to violet | Blue to greenish-blue | Colorless, yellow-gold, red, green, blue |
| Cleavage | Poor to moderate | None | None |
| Luster | Vitreous | Waxy to greasy | Vitreous |
| Transparency | Transparent to translucent | Opaque | Transparent to translucent |
| Treatments | Heat treatment | Resin or oil stabilization | Heat treatment |
| Care | Gentle cleaning, avoid chemicals | Gentle cleaning, avoid chemicals and heat | Easy to clean, avoid scratches |
Cultural and Metaphysical Significance
Tanzanite
- Spiritual Growth and Emotional Balance: Tanzanite is often used in spiritual practices to promote inner peace, emotional healing, and intuitive development.
- Success and Prosperity: It is believed to enhance ambition, creativity, and success in both personal and professional life.
- Compassion and Harmony: Tanzanite is associated with empathy, understanding, and compassion, making it a popular stone for resolving conflicts and promoting harmony.
Turquoise
- Protection and Healing: Turquoise has long been used as a protective stone, believed to ward off negative energies and promote physical and emotional healing.
- Wisdom and Communication: It is associated with mental clarity, wisdom, and effective communication, making it a popular stone for public speakers and leaders.
- Balance and Serenity: Turquoise is believed to promote emotional balance and inner peace, helping individuals navigate stress and anxiety.
Zircon
- Intuition and Insight: Zircon is associated with intuition, insight, and spiritual awareness, making it a popular stone for meditation and spiritual practices.
- Creativity and Motivation: It is believed to enhance creativity, motivation, and inspiration, helping individuals achieve their goals and aspirations.
- Rest and Renewal: Zircon is also associated with restful sleep and physical rejuvenation, making it a popular stone for those seeking rest and relaxation.
Conclusion
December 19th is a unique and meaningful date in the world of birthstones, as it is associated with tanzanite, turquoise, and zircon—three gemstones that each carry their own rich history, cultural significance, and gemological properties. Together, these stones form a well-rounded and powerful set of energies that can support the wearer in various aspects of life.
Tanzanite, with its rare origin and stunning blue-violet hues, represents spiritual growth, emotional balance, and success. Turquoise, an ancient stone of protection and healing, is believed to bring wisdom, harmony, and positive energy. Zircon, with its brilliant fire and ancient origins, is associated with intuition, creativity, and motivation.
By understanding the unique properties and significance of these gemstones, individuals can choose the one that resonates most with their personal journey and goals. Whether used in jewelry, meditation, or spiritual practices, these December birthstones continue to capture the imagination and admiration of gemstone enthusiasts and spiritual seekers alike.