December, the last month of the year, is associated with a rich and varied selection of gemstones, each with its own unique history, symbolism, and gemological properties. Unlike other months, December has three officially recognized birthstones: turquoise, zircon, and tanzanite. This diversity reflects both historical traditions and modern adaptations in gemstone culture. Each of these stones has been cherished for different reasons across various cultures and eras, making December one of the most symbolically rich months in the birthstone calendar.
This article explores the history, geological properties, symbolic significance, and care of these three December birthstones, drawing from a range of authoritative and historical sources. Whether you are a gemstone enthusiast, a jewelry buyer, or simply curious about the meaning behind December's gems, this article will provide you with a comprehensive and insightful overview of the stones that celebrate the final month of the year.
History and Lore
The concept of birthstones dates back thousands of years, with the earliest known references appearing in the biblical Book of Exodus, which lists 12 stones for the breastplate of the High Priest of Israel. These ancient stones were believed to have protective and spiritual powers. Over time, different cultures adopted and adapted these lists, assigning specific gemstones to months of the year. December's gemstone selection has evolved significantly, reflecting both historical traditions and modern preferences.
In the 19th century, December was primarily associated with turquoise, which was widely recognized as a December birthstone. The use of turquoise as a protective and spiritual gemstone can be traced back to ancient Egypt, where it was highly valued for its beauty and believed to bring good fortune. Pharaohs and other Egyptian rulers adorned themselves with turquoise jewelry, and it was also used in amulets and religious artifacts.
By the mid-20th century, lapis lazuli was considered a December birthstone, particularly before 1952. This gemstone, known for its deep blue color and golden flecks, was cherished by ancient royalty and artists. However, in 1952, zircon was added to the December birthstone list by the Jewelry Industry Council of America. Zircon, especially blue zircon, was chosen for its vibrant color and its growing popularity in jewelry.
In 2002, the list expanded again with the addition of tanzanite, a relatively new gemstone discovered in Tanzania in the 1960s. Tanzanite's striking blue-violet color and its rarity made it a popular choice for December, and it has since become a well-recognized birthstone for the month.
While blue topaz, ruby, chrysoprase, onyx, bloodstone, and lapis lazuli have also been associated with December in various historical and cultural contexts, the modern birthstone list officially recognizes turquoise, zircon, and tanzanite.
The evolution of December's birthstone list demonstrates the changing preferences and values of different eras. What was once a stone reserved for royalty and spiritual use is now a symbol of personal identity and style. This shift reflects not only the changing role of gemstones in society but also the growing appreciation for their beauty, symbolism, and scientific properties.
Geological Formation and Sources
The gemstones associated with December—turquoise, zircon, and tanzanite—each have distinct geological origins and are found in specific locations around the world. Understanding their formation processes and sources provides insight into their rarity, value, and unique characteristics.
Turquoise
Turquoise is a hydrated phosphate of aluminum and copper, with the chemical formula CuAl₆(PO₄)₄(OH)₈·4H₂O. It forms in arid regions where copper-rich deposits are exposed to water. The process begins when rainwater or melted snow percolates through copper porphyry deposits. This water reacts with copper sulfides in the ore to form an acidic solution, which then interacts with aluminum and potassium in the surrounding rocks. This chemical reaction results in the precipitation of turquoise within cavities in the rock.
Turquoise is typically found in weathered volcanic and sedimentary rocks in arid climates. Major sources of turquoise include the United States (particularly Arizona and Nevada), Afghanistan, China, Egypt, Iran, and Mexico. Each location produces turquoise with slightly different colors and matrix patterns, making each deposit unique.
One of the most notable characteristics of turquoise is its porosity. This porosity makes it relatively soft, with a hardness of 5 to 6 on the Mohs scale. Because of this, turquoise can be easily scratched or broken if not handled with care. It is also susceptible to discoloration from oils, pigments, and changes in water content.
Zircon
Zircon is a silicate mineral with the chemical formula ZrSiO₄. It is one of the oldest minerals on Earth, with some zircon crystals dating back over 4 billion years. Zircon forms in igneous rocks and is often found in metamorphic and sedimentary rocks as well. It is known for its high refractive index and dispersion, which gives it a brilliant sparkle when cut and polished.
Zircon can occur in a variety of colors, including colorless, yellow, red, brown, green, and blue. The blue zircon, which is most commonly associated with December, is created through heat treatment. This treatment enhances the stone's natural color and makes it more stable.
Zircon is found in many parts of the world, including Australia, Brazil, Cambodia, India, Madagascar, and Thailand. Each location produces zircon with slightly different characteristics, and the gemstone's color and clarity can vary depending on the source.
Zircon is a relatively hard gemstone, with a hardness of 6.5 to 7.5 on the Mohs scale. This makes it more durable than turquoise and suitable for everyday wear in jewelry.
Tanzanite
Tanzanite is a relatively new gemstone, first discovered in Tanzania in 1967. It is a variety of the mineral zoisite, with the chemical formula Ca₂Al₃(SiO₄)(Si₂O₇)O(OH)₁·H₂O. Tanzanite is known for its striking blue-violet color, which is caused by trace amounts of vanadium in the crystal structure.
Tanzanite is found exclusively in the Merelani Hills near Arusha in northern Tanzania. This limited source makes tanzanite one of the rarest gemstones in the world. The gemstone is typically found in metamorphic rocks and is mined through open-pit and underground methods.
Tanzanite has a hardness of 6 to 7 on the Mohs scale, making it durable enough for jewelry but still requiring careful handling. It is also sensitive to heat and light, which can cause it to fade or change color over time. Because of this, tanzanite is often heat-treated to stabilize its color and enhance its brilliance.
Gemological Properties
Each of the three December birthstones—turquoise, zircon, and tanzanite—has unique gemological properties that define their appearance, durability, and value. Understanding these properties is essential for gemstone enthusiasts, jewelers, and collectors who wish to appreciate and care for these stones.
Turquoise
Turquoise is a semi-translucent to opaque gemstone with a hardness of 5 to 6 on the Mohs scale. Its color ranges from deep blue to green, depending on the proportions of copper and aluminum in its chemical composition. Turquoise often contains veins of matrix, which are remnants of the rock in which it formed. These matrix patterns add to the stone's visual appeal and can vary in color and density.
One of the most notable characteristics of turquoise is its porosity. This porosity makes it relatively soft and susceptible to scratches, chips, and discoloration. Because of this, turquoise is best suited for low-wear jewelry pieces such as pendants and earrings. It is not recommended for rings and bracelets, where it is more likely to be damaged.
Turquoise is also sensitive to oils, pigments, and changes in water content. This means that it can easily be discolored or altered if exposed to harsh chemicals, excessive heat, or prolonged exposure to sunlight.
Zircon
Zircon is a silicate mineral with a hardness of 6.5 to 7.5 on the Mohs scale, making it significantly harder than turquoise. It is known for its high refractive index and dispersion, which give it a brilliant sparkle when cut and polished. Zircon can occur in a variety of colors, including colorless, yellow, red, brown, green, and blue. The blue zircon, which is most commonly associated with December, is created through heat treatment.
Zircon's high refractive index and dispersion make it an excellent choice for jewelry that requires a brilliant and eye-catching appearance. It is also relatively durable, making it suitable for everyday wear in rings, earrings, and pendants.
Unlike turquoise, zircon is not porous and is not as sensitive to changes in water content or exposure to oils and pigments. However, it is still important to handle zircon with care, as it can be scratched or chipped if exposed to excessive force.
Tanzanite
Tanzanite is a relatively new gemstone, with a hardness of 6 to 7 on the Mohs scale. It is known for its striking blue-violet color, which is caused by trace amounts of vanadium in the crystal structure. Tanzanite is a variety of the mineral zoisite and is found exclusively in Tanzania.
Tanzanite is typically found in metamorphic rocks and is mined through open-pit and underground methods. Because of its limited source, tanzanite is one of the rarest gemstones in the world.
Tanzanite is sensitive to heat and light, which can cause it to fade or change color over time. Because of this, tanzanite is often heat-treated to stabilize its color and enhance its brilliance. This treatment is generally stable and does not affect the stone's durability.
Tanzanite is also relatively durable, making it suitable for jewelry such as rings, earrings, and pendants. However, it is still important to handle tanzanite with care, as it can be scratched or chipped if exposed to excessive force.
Symbolism and Metaphysical Beliefs
The December birthstones—turquoise, zircon, and tanzanite—have been associated with various symbolic meanings and metaphysical beliefs across different cultures and historical periods. These beliefs often reflect the gemstone's physical properties, color, and cultural significance.
Turquoise
Turquoise has long been regarded as a stone of protection, prosperity, and spiritual connection. In ancient Egypt, it was believed to bring good fortune and was used in amulets and religious artifacts. Pharaohs and other rulers adorned themselves with turquoise jewelry, and it was also used in funerary practices to protect the deceased in the afterlife.
In Native American cultures, turquoise is considered a sacred stone that represents wisdom, protection, and harmony with nature. It is often used in spiritual rituals and is believed to have healing properties. Many Native American tribes use turquoise in jewelry and ceremonial objects to connect with the spiritual world.
In Hindu traditions, turquoise is associated with the month of December and is believed to stimulate self-esteem, improve concentration, and encourage spiritual growth. It is also considered a stone of meditation, helping individuals connect with higher sources of wisdom.
Zircon
Zircon is often associated with emotional balance, joy, and spiritual clarity. It is believed to help individuals find inner peace and release negative emotions. Zircon is also thought to enhance intuition and help individuals connect with their higher self.
In some cultures, zircon is considered a stone of good fortune and prosperity. It is believed to attract positive energy and help individuals achieve their goals. Zircon is also associated with protection and is often used in amulets and talismans to ward off negative influences.
Zircon's vibrant colors and brilliant sparkle make it a popular choice for those seeking to enhance their personal power and confidence. It is also believed to help individuals express their emotions more clearly and communicate with others in a calm and compassionate manner.
Tanzanite
Tanzanite is a relatively new gemstone, but it has already been associated with various symbolic meanings and metaphysical beliefs. It is considered a stone of transformation, change, and spiritual growth. Because of its limited source and rarity, tanzanite is also associated with exclusivity and uniqueness.
Tanzanite is believed to help individuals release old patterns and embrace new possibilities. It is often used in meditation to enhance spiritual awareness and connect with higher dimensions of consciousness. Tanzanite is also thought to promote emotional healing and help individuals process difficult emotions.
In some cultures, tanzanite is considered a protective stone that shields the wearer from negative influences. It is also believed to enhance communication and help individuals express their thoughts and feelings more clearly. Tanzanite is often used in jewelry to symbolize personal growth, transformation, and the ability to embrace change.
Care and Cleaning
Proper care and cleaning are essential for preserving the beauty and longevity of the December birthstones—turquoise, zircon, and tanzanite. Each of these gemstones has different care requirements due to their unique physical properties and sensitivity to environmental factors.
Turquoise
Turquoise requires special care due to its porosity and sensitivity to oils, pigments, and changes in water content. It should be kept away from harsh chemicals, excessive heat, and direct sunlight, as these can cause it to fade or discolor.
To clean turquoise, it is best to use a soft, damp cloth and mild soap. Avoid using ultrasonic cleaners or steam cleaners, as these can damage the stone. Turquoise can also be cleaned by placing it on a piece of selenite or moving it through the smoke of sage to cleanse its energy.
Turquoise should be stored in a cool, dry place to prevent it from drying out or losing its color. It is also a good idea to remove turquoise jewelry daily to allow the stone to rest and recover from any exposure to oils or moisture.
Zircon
Zircon is relatively durable and can be cleaned with mild soap and warm water. A soft cloth or brush can be used to remove any dirt or debris from the surface of the stone.
Ultrasonic cleaners can also be used to clean zircon, as long as the stone is not heat-sensitive. However, it is best to avoid using steam cleaners, as these can cause the stone to crack or chip.
Zircon should be stored in a cool, dry place to prevent it from becoming too hot or exposed to excessive light. It is also a good idea to remove zircon jewelry daily to allow the stone to rest and recover from any exposure to oils or moisture.
Tanzanite
Tanzanite is sensitive to heat and light, so it should be kept away from direct sunlight and excessive heat. It is best to store tanzanite in a cool, dark place to prevent it from fading or changing color.
To clean tanzanite, use mild soap and warm water with a soft cloth or brush. Avoid using ultrasonic or steam cleaners, as these can cause the stone to crack or lose its color.
Tanzanite should also be removed daily to allow it to rest and recover from any exposure to oils or moisture. It is a good idea to store tanzanite in a separate compartment to prevent it from coming into contact with other gemstones that may scratch or chip it.
Conclusion
December is a month rich in symbolism and tradition, and its birthstones—turquoise, zircon, and tanzanite—reflect this richness in their history, beauty, and meaning. Each of these gemstones has a unique story, from the ancient traditions of Egypt and Native America to the modern discoveries of the 20th century.
Turquoise, with its deep blue-green color and historical significance, has been cherished for millennia as a stone of protection, prosperity, and spiritual connection. Zircon, with its brilliant sparkle and vibrant colors, has been associated with emotional balance, joy, and spiritual clarity. Tanzanite, a relatively new gemstone, is linked to transformation, change, and spiritual growth, making it a powerful symbol for the final month of the year.
Understanding the geological properties, historical significance, and symbolic meanings of these December birthstones allows us to appreciate their beauty and value on a deeper level. Whether worn as a personal adornment or used in spiritual practices, these gemstones continue to inspire and connect us to the past, the present, and the future.