December, the final month of the calendar year, is marked not only by the cold winds and holiday cheer but also by a collection of four unique and beautiful birthstones: blue zircon, tanzanite, turquoise, and blue topaz. Each of these stones carries its own distinct color, history, and set of symbolic meanings. While turquoise has been the traditional December birthstone for centuries, the modern birthstone chart now includes blue topaz, tanzanite, and zircon as equally valid choices. This article explores each of these gemstones in detail, drawing from authoritative gemological sources and historical records, to provide a comprehensive overview of their properties, origins, symbolism, and care requirements.
History and Lore of December Birthstones
Turquoise: The Ancient and Revered
Turquoise is perhaps the most historically significant of the December birthstones. Its use dates back thousands of years, with archaeological evidence of its presence in ancient Egyptian tombs, as well as in artifacts from the Indus Valley Civilization and the Americas. Turquoise was highly valued by the ancient Egyptians, who believed it had protective and spiritual powers. It was often inlaid into jewelry and amulets worn by both royalty and commoners.
In Native American cultures, particularly among the Navajo and Zuni tribes, turquoise was considered a sacred stone. It was used in ceremonies and believed to bring good fortune, protection, and harmony. The stone was also associated with the sky and water, symbolizing the life-giving forces of nature.
Turquoise was once thought to have the ability to predict danger. One legend suggests that if a turquoise gemstone turned green, it was a sign of impending disaster. Another belief held that turquoise could fall apart or break if a catastrophe was near.
Despite its historical significance, turquoise is relatively soft, with a hardness of 5 to 6 on the Mohs scale. This makes it more prone to scratches and damage, which is an important consideration for its use in jewelry.
Tanzanite: The Modern Discovery
Tanzanite is a much newer addition to the December birthstone lineup, having been discovered in the 1960s in Tanzania. It was first identified in 1967 by a miner named Manuel de Souza, who found a violet-colored crystal in the Merelani Hills. The gem was later named by Tiffany & Co. in honor of its country of origin.
Tanzanite is known for its striking color, which can shift between blue and violet depending on the angle of light. This trichroic property is due to the presence of vanadium in the crystal structure. Tanzanite is a variety of the mineral zoisite and is only found in Tanzania, making it one of the rarest gemstones in the world.
Tanzanite quickly gained popularity due to its unique color and the fact that it was a new gemstone in the market. It was officially recognized as a December birthstone in the modern birthstone chart, adding a vibrant and contemporary option to the selection available for December birthdays.
Blue Zircon: The Forgotten Gem
Blue zircon is another ancient gemstone that has been used for centuries but has only recently regained popularity. Zircon, in its natural form, occurs in a range of colors including red, brown, green, and yellow. However, when heat-treated, zircon can display a brilliant blue color, which is highly sought after.
Zircon has a long history in jewelry and was particularly popular during the Middle Ages. During this time, it was believed to have the power to induce sleep and ward off evil spirits. Blue zircon is also noted for its high refractive index and dispersion, giving it a fire and brilliance that is often compared to that of a diamond.
Zircon is a durable gemstone, with a hardness of 6.5 to 7.5 on the Mohs scale. It is also relatively affordable compared to other blue gemstones, making it a popular choice for jewelry.
Blue Topaz: The Modern Addition
Blue topaz is the most recent addition to the December birthstone list. While topaz has been known and used for centuries, it is only in recent decades that blue topaz has become widely available and recognized as a December birthstone.
Topaz is a silicate mineral that can occur in a range of colors including yellow, orange, pink, and blue. Blue topaz is typically created through irradiation or heat treatment of colorless or yellow topaz. The blue color is stable and permanent once treated.
Blue topaz is known for its clarity and brilliance, making it a popular choice for a variety of jewelry styles. It has a hardness of 8 on the Mohs scale, which makes it relatively durable and suitable for everyday wear.
Blue topaz is also associated with spiritual and emotional benefits. It is believed to enhance creativity, increase inner strength, and promote wisdom and beauty. These properties make it an appealing choice for those born in December who seek a gemstone that resonates with their personality and values.
Geological Formation and Sources
Formation of Turquoise
Turquoise is a hydrated phosphate of aluminum and copper. It forms in the oxidation zones of copper deposits, typically in arid regions where the conditions are right for the slow evaporation of water and the formation of the mineral. The presence of different elements such as iron, phosphorus, and copper can influence the color of the gemstone.
The most famous sources of turquoise are in the American Southwest, particularly in Arizona and New Mexico. Other notable sources include Iran, China, and Egypt. The quality of turquoise varies depending on the location and the specific conditions under which it forms. High-quality turquoise is usually a vibrant blue with minimal matrix or webbing.
Formation of Tanzanite
Tanzanite is a type of zoisite that contains vanadium, which gives it its characteristic blue and violet color. It forms under high-pressure and high-temperature conditions in metamorphic rocks. The Merelani Hills in Tanzania are the only place in the world where tanzanite occurs naturally.
The formation of tanzanite is relatively rare due to the specific geological conditions required. This rarity contributes to its high value and limited availability. Tanzanite is mined primarily in open pits, and the process involves careful extraction to avoid damaging the delicate crystals.
Formation of Blue Zircon
Zircon is a zirconium silicate that can occur in a variety of colors depending on the impurities present. Blue zircon is typically the result of heat treatment applied to natural zircon. This treatment removes the yellow or brown color and enhances the blue hue.
Zircon forms in igneous and metamorphic rocks and is found in a number of countries including Australia, Thailand, India, and Brazil. The most valuable zircons are those with a deep blue color and high clarity. Zircon is also known for its high refractive index and dispersion, which contribute to its brilliance.
Formation of Blue Topaz
Topaz is a silicate mineral that forms in igneous rocks, particularly in pegmatites. Blue topaz is typically colorless or yellow in its natural state. The blue color is achieved through irradiation or heat treatment, which alters the structure of the mineral and stabilizes the color.
Blue topaz is found in a number of countries including Brazil, Nigeria, and the United States. The most significant deposits are in Brazil, where large quantities of colorless topaz are treated to produce the blue color. Blue topaz is relatively abundant and affordable, making it a popular choice for jewelry.
Gemological Properties
| Gemstone | Color | Hardness (Mohs Scale) | Composition | Refractive Index | Cleavage | Translucency |
|---|---|---|---|---|---|---|
| Turquoise | Blue, green, greenish-yellow | 5–6 | Hydrated phosphate of aluminum and copper | 1.60–1.64 | None | Opaque to translucent |
| Tanzanite | Blue, violet, purple | 6–7 | Calcium aluminum silicate with vanadium | 1.69–1.70 | Perfect | Transparent |
| Blue Zircon | Blue | 6.5–7.5 | Zirconium silicate | 1.92–2.00 | Perfect | Transparent |
| Blue Topaz | Blue | 8 | Silicate of aluminum and fluorine | 1.61–1.63 | None | Transparent |
Turquoise
Turquoise is a relatively soft gemstone with a hardness of 5 to 6 on the Mohs scale. It is composed of hydrated phosphate of aluminum and copper. Its refractive index ranges from 1.60 to 1.64, and it is typically opaque to translucent. Turquoise does not have cleavage, but it can be easily fractured due to its softness.
Tanzanite
Tanzanite has a hardness of 6 to 7 on the Mohs scale. It is a calcium aluminum silicate with vanadium, which gives it its unique blue and violet color. Tanzanite has a refractive index of 1.69 to 1.70 and is transparent. It has perfect cleavage, which means it can be easily fractured along specific planes.
Blue Zircon
Blue zircon has a hardness of 6.5 to 7.5 on the Mohs scale. It is a zirconium silicate and has a high refractive index of 1.92 to 2.00. Blue zircon is transparent and has perfect cleavage, making it susceptible to damage if not handled carefully.
Blue Topaz
Blue topaz has a hardness of 8 on the Mohs scale, making it one of the harder gemstones among the December birthstones. It is a silicate of aluminum and fluorine and has a refractive index of 1.61 to 1.63. Blue topaz is transparent and does not have cleavage, making it more durable than the other December birthstones.
Symbolism and Metaphysical Beliefs
Turquoise
Turquoise has long been associated with positive energy and protection. Ancient cultures believed that it could ward off evil spirits and bring good fortune. In Native American traditions, turquoise was used in rituals and was believed to connect the earth and sky.
Turquoise is also associated with health and healing. Some believe that it can help with respiratory issues and promote overall well-being. It is also thought to bring calmness and balance to the mind and body.
In Hindu mysticism, turquoise was believed to bring wealth when viewed after a new moon. It was also used in protective amulets to ensure the wearer's safety and happiness.
Tanzanite
Tanzanite is associated with emotional healing and spiritual growth. It is believed to enhance intuition and promote a deeper connection with the spiritual world. Tanzanite is also thought to help with emotional balance and can aid in the resolution of past traumas.
As a relatively new gemstone, tanzanite has not had the same historical symbolism as turquoise. However, its rarity and beauty have made it a symbol of exclusivity and luxury.
Blue Zircon
Blue zircon is believed to have the power to induce sleep and ward off evil spirits. During the Middle Ages, it was used in protective amulets to ensure peaceful rest and to keep nightmares at bay.
Blue zircon is also associated with wisdom and clarity of thought. It is believed to enhance mental focus and stimulate intellectual growth. It is a popular choice for those seeking to improve their cognitive abilities and decision-making skills.
Blue Topaz
Blue topaz is associated with inner strength, creativity, and wisdom. It is believed to enhance the wearer's ability to think clearly and make sound decisions. It is also thought to promote emotional stability and help with stress relief.
Blue topaz is often used in meditation practices to enhance spiritual awareness and promote a sense of calm. It is believed to help the wearer connect with their higher self and achieve a greater sense of purpose.
Care and Cleaning
Turquoise
Turquoise is a relatively soft gemstone and requires special care to prevent damage. It should be cleaned with a soft cloth and mild soap. Avoid using ultrasonic or steam cleaners, as these can cause the gemstone to crack or lose its color.
Turquoise should also be kept away from harsh chemicals and abrasive materials. It is best stored separately from other gemstones to prevent scratches and abrasions.
Tanzanite
Tanzanite has perfect cleavage, making it susceptible to chipping and breaking. It should be cleaned with a soft cloth and mild soap, and ultrasonic or steam cleaners should be avoided.
Tanzanite should be stored in a secure, padded container to prevent damage from other gemstones. It should also be kept away from sharp objects and abrasive materials.
Blue Zircon
Blue zircon is relatively durable but has perfect cleavage, which means it can be easily damaged. It should be cleaned with a soft cloth and mild soap. Avoid using ultrasonic or steam cleaners, as these can cause the gemstone to fracture.
Blue zircon should be stored separately from other gemstones to prevent scratches and abrasions. It should also be kept away from harsh chemicals and abrasive materials.
Blue Topaz
Blue topaz is one of the harder gemstones among the December birthstones, with a hardness of 8 on the Mohs scale. It can be cleaned with a soft cloth and mild soap. Ultrasonic and steam cleaners can be used, but it is best to avoid them if the gemstone has any inclusions or surface treatments.
Blue topaz should be stored in a secure, padded container to prevent damage from other gemstones. It should also be kept away from sharp objects and abrasive materials.
Conclusion
December is a month rich in tradition and beauty, and the four birthstones associated with it reflect this richness. Turquoise, tanzanite, blue zircon, and blue topaz each offer a unique blend of color, history, and symbolism. Whether you are drawn to the ancient traditions surrounding turquoise, the modern elegance of tanzanite, the brilliance of blue zircon, or the clarity and durability of blue topaz, there is a December birthstone that is sure to resonate with you.
Understanding the properties, origins, and symbolism of these gemstones allows for a deeper appreciation of their beauty and significance. Whether you are a gemstone enthusiast, a jewelry buyer, or a student of gemology, the December birthstones offer a fascinating and rewarding subject of study and admiration.