December 7th is a date rich in historical and symbolic significance, marked not only by the Pearl Harbor attack in 1941 but also by its association with a unique set of gemstones. For those born on this date, the birthstones are more than just beautiful adornments—they are windows into the geological, cultural, and spiritual heritage of humanity. On December 7th, three primary birthstones are recognized: turquoise, tanzanite, and zircon, with bloodstone and ruby also appearing in alternative or historical listings. Each of these gemstones carries its own distinct character, from the serene blue of turquoise to the vibrant violet of tanzanite and the fiery brilliance of zircon. This article delves into the geological properties, historical uses, cultural symbolism, and practical care of these December 7th birthstones, drawing exclusively from the provided materials to ensure accuracy and authenticity.
History and Lore
The tradition of birthstones has ancient roots, with references appearing in biblical texts and early medieval practices. The modern concept of birthstones is largely influenced by the list of stones found on the breastplate of Aaron from the Old Testament and the foundation of New Jerusalem as described in the Book of Revelation. These references have evolved over time, and the list of birthstones for each month has seen multiple revisions. For December, the selection of gemstones has been particularly dynamic, with various stones being added and removed over the centuries.
According to the National Association of Jewellers (now the Jewellers of America) in 1912, turquoise was designated as the primary birthstone for December, with lapis lazuli as an alternative. By 1952, zircon, and specifically blue zircon, was added to the list by the Jewelry Industry Council of America. In 2002, tanzanite was officially recognized as a December birthstone, making it one of the more recent additions. This evolution reflects not only the changing trends in jewelry but also the growing appreciation for the unique properties and beauty of these gemstones.
The inclusion of multiple birthstones for December serves a practical purpose as well. December birthstones offer a range of options in terms of color, hardness, and price, allowing individuals to choose a gemstone that best suits their preferences and lifestyle. This diversity also reflects the global and historical reach of these stones. Turquoise, for example, has been used in jewelry and amulets for thousands of years, particularly in Mesoamerican and Middle Eastern cultures. Zircon, one of the oldest minerals on Earth, has been found in ancient geological formations and has been revered for its brilliance and fire. Tanzanite, on the other hand, is a relatively modern discovery, found only in the Merelani Hills of Tanzania, near Mount Kilimanjaro, and has since become a symbol of rarity and exclusivity.
Geological Formation and Sources
Understanding the geological origins of December 7th birthstones provides insight into their rarity, durability, and value. Each of these gemstones forms under specific geological conditions, resulting in distinct physical and chemical properties.
Turquoise
Turquoise is a phosphate mineral that forms in the oxidation zones of copper deposits. It is typically found in limestone and sandstone formations, where water carrying copper and phosphate ions precipitates to form the stone. The most historically significant sources of turquoise include Iran, Nepal, and the American Southwest, particularly Arizona and New Mexico. The color of turquoise varies from deep blue to green, depending on the amount of copper (which causes the blue) and iron (which causes the green) present in the mineral.
Zircon
Zircon is a zirconium silicate that forms in igneous rocks, particularly in granite and basalt. It is one of the oldest minerals on Earth, with some zircon crystals dated to over 4 billion years old. Zircon can occur in a wide range of colors, including brown, yellow, red, green, and blue, with the blue variety being the most popular as a birthstone. This blue color is achieved through heat treatment, which stabilizes the color and enhances the stone's brilliance. Zircon is found in various locations worldwide, including Madagascar, India, and Brazil.
Tanzanite
Tanzanite is a trigonal mineral composed of calcium aluminum silicate with trace amounts of vanadium, which is responsible for its blue to violet color. Unlike turquoise and zircon, tanzanite is found in only one location on Earth: the Merelani Hills in Tanzania, near the Great Rift Valley. The geological conditions required for tanzanite formation are extremely rare, involving the collision of tectonic plates and the presence of vanadium-rich metamorphic rock. This exclusivity has made tanzanite a highly sought-after gemstone since its discovery in the 1960s.
Gemological Properties
Each of the December 7th birthstones has unique physical and optical properties that contribute to their beauty and durability.
Turquoise
- Color: Ranges from deep blue to green, with characteristic matrix patterns of black, brown, or white veins.
- Hardness: 5 to 6 on the Mohs scale, making it relatively soft and prone to scratches.
- Luster: Waxy to greasy.
- Transparency: Opaque.
- Specific Gravity: 2.6 to 2.8.
- Cleavage: None; however, it is porous and can absorb oils and lotions.
Zircon
- Color: Available in a wide range of colors, including brown, yellow, red, green, and blue (especially popular as a birthstone).
- Hardness: 6 to 7.5 on the Mohs scale, depending on the crystal structure.
- Luster: Vitreous to resinous.
- Transparency: Transparent to translucent.
- Specific Gravity: 3.9 to 4.7.
- Refractive Index: 1.92 to 2.01.
- Cleavage: Perfect in one direction, which makes it vulnerable to chipping.
Tanzanite
- Color: Blue to violet, with a trichroic nature, meaning it can appear different colors depending on the angle of light.
- Hardness: 6 to 7 on the Mohs scale.
- Luster: Vitreous.
- Transparency: Transparent to translucent.
- Specific Gravity: 3.1 to 3.4.
- Refractive Index: 1.694 to 1.701.
- Cleavage: Perfect in one direction, which makes it susceptible to cracking.
| Property | Turquoise | Zircon | Tanzanite |
|---|---|---|---|
| Color | Blue to green | Varied (blue popular) | Blue to violet |
| Hardness | 5–6 | 6–7.5 | 6–7 |
| Luster | Waxy to greasy | Vitreous to resinous | Vitreous |
| Transparency | Opaque | Transparent to translucent | Transparent to translucent |
| Specific Gravity | 2.6–2.8 | 3.9–4.7 | 3.1–3.4 |
| Cleavage | None | Perfect in one direction | Perfect in one direction |
Symbolism and Metaphysical Beliefs
The December 7th birthstones are not only valued for their beauty but also for their symbolic and metaphysical significance. These beliefs have been passed down through generations and continue to influence the way these stones are used in jewelry and spiritual practices.
Turquoise
Turquoise has long been associated with protection, wisdom, and communication. In ancient Egyptian, Persian, and Native American cultures, turquoise was believed to bring good fortune, heal the body, and protect the wearer from harm. It was also used as an amulet to ward off evil spirits and promote inner peace. In modern times, turquoise is often linked to mental clarity, emotional stability, and open communication.
Zircon
Zircon is known for its brilliance and fire, and this has translated into its metaphysical properties. It is believed to enhance mental clarity, stimulate creativity, and awaken spiritual insight. Zircon is also associated with time and memory, as it is one of the oldest minerals on Earth. In some traditions, zircon is used to clear negative energy and bring balance to the mind and body.
Tanzanite
Tanzanite is considered a stone of transformation and emotional healing. It is believed to help individuals release old patterns, embrace new perspectives, and develop emotional strength. Tanzanite is also associated with intuition and spiritual growth, making it a popular choice for those seeking inner peace and harmony.
Care and Cleaning
Given their varying levels of hardness and sensitivity to environmental factors, the care and cleaning of December 7th birthstones require careful consideration.
Turquoise
Due to its porosity and low hardness, turquoise should be handled with care. It is best to avoid exposure to heat, chemicals, and prolonged sunlight, which can cause it to fade or dry out. Cleaning can be done with warm, soapy water and a soft cloth. Ultrasonic and steam cleaners are not recommended, as they can damage the stone.
Zircon
Zircon is relatively durable, but its perfect cleavage makes it prone to chipping. It should be stored separately from harder gemstones to avoid scratches. Cleaning can be done with warm, soapy water and a soft brush. Ultrasonic cleaners may be used cautiously, but steam cleaners are not recommended.
Tanzanite
Tanzanite is sensitive to heat and sudden temperature changes, which can cause it to crack. It is also susceptible to chemical damage, particularly from hydrochloric and hydrofluoric acids. Cleaning should be done with warm, soapy water and a soft cloth. Ultrasonic and steam cleaners are not recommended for tanzanite.
Conclusion
The birthstones for December 7th—turquoise, tanzanite, and zircon—each carry a unique story, shaped by their geological origins, historical significance, and cultural symbolism. These gemstones are not only beautiful but also deeply meaningful, representing a connection to the past and a source of inspiration for the future. Whether chosen for their color, rarity, or spiritual properties, these December birthstones offer a rich tapestry of choices for jewelry lovers and gemstone enthusiasts alike. As we continue to explore and appreciate the natural world, these stones remind us of the enduring power and beauty of the Earth’s treasures.