December, the twelfth month of the year, is symbolically adorned with a rich palette of blue gemstones. Those born in this month are fortunate to have a choice of four beautiful birthstones: blue topaz, blue zircon, tanzanite, and turquoise. Each of these gemstones carries its own unique geological properties, historical significance, and cultural symbolism. This article delves into the characteristics and allure of the December birthstones, offering a comprehensive overview of their origins, gemological traits, care instructions, and the meanings they have held across time.
December is a month of celebration and reflection, and its birthstones reflect the cool tones of winter and the mystery of the night sky. The four blue gemstones associated with December—blue topaz, blue zircon, tanzanite, and turquoise—each offer a distinct blend of beauty and meaning. While blue is the common thread, the individual properties, formation processes, and cultural legacies of these stones vary greatly.
In the following sections, we will explore the history and lore behind each of these December birthstones, their geological origins and properties, the metaphysical beliefs they have inspired, and how to care for them to preserve their brilliance.
History and Lore of the December Birthstones
Each December birthstone has a rich and varied history, with roots in ancient civilizations and enduring symbolism across cultures.
Tanzanite: A Modern Discovery with Ancient Roots
Tanzanite is the youngest of the December birthstones, discovered in 1967 in the Merelani Hills of Tanzania. Prior to this, the gem existed in nature but was not recognized as a distinct stone. Tanzanite is a type of zoisite that, when heat-treated, transforms from a brownish color into its iconic blue-violet hues. The name “tanzanite” is derived from the country of Tanzania, where it is the only known source in the world.
Although tanzanite is a relatively new discovery, its allure quickly captured the imagination of jewelers and collectors. It is associated with transformation, psychic awakening, and spiritual growth. Some metaphysical traditions suggest that tanzanite can activate the throat, third-eye, and crown chakras, enabling the wearer to access higher states of consciousness and enhance communication with the divine.
Turquoise: A Stone of Protection and Prosperity
Turquoise, one of the oldest known gemstones, has been cherished for thousands of years. Its use dates back to ancient Egypt, where it was valued for its protective and healing properties. Pharaohs and other rulers adorned themselves with turquoise to symbolize power and divine favor. In Chinese culture, turquoise was carved into intricate jewelry and amulets over 3,000 years ago.
The name "turquoise" comes from the French word pierre turquoise, meaning "Turkish stone," reflecting its historical trade route through Turkey. In the 13th century, it was believed that turquoise could protect the wearer from falling, particularly from horseback. It was also thought to break into pieces at the approach of disaster, acting as a warning. In Hindu tradition, seeing turquoise after the new moon was believed to bring great wealth.
Turquoise has continued to be a symbol of protection and good fortune in many cultures, including Native American tribes, who used it in ceremonial jewelry and for spiritual purposes.
Blue Zircon: A Timeless Stone of Clarity
Zircon is one of the oldest minerals on Earth, with some zircon crystals found in Australia dating back over 4 billion years. Blue zircon, which is the most common and popular variety of zircon used in jewelry, is often produced through heat treatment. Its vivid blue color and high refractive index give it a brilliance that rivals that of diamonds.
Zircon has long been associated with clarity, wisdom, and the enhancement of spiritual insight. In medieval Europe, zircon was believed to have protective qualities and was used to ward off evil. It was also considered a stone of good omen and was worn by travelers for safe passage.
The December birthstone zircon is particularly interesting because it is often found near sapphire sources. Countries like Sri Lanka, Australia, Myanmar, Vietnam, and Cambodia are known for producing both zircon and sapphire, though zircon is far more abundant and affordable.
Blue Topaz: A Versatile and Radiant Gemstone
Blue topaz, the most recently designated December birthstone, has become a popular choice due to its affordability and striking color. Natural blue topaz is rare, and most of the blue topaz available on the market today is created through irradiation of naturally colorless topaz. The process enhances the gem’s color, resulting in a range of blues, from the deep inky blue of London Blue to the vibrant Swiss Blue and the lighter Sky Blue.
Topaz, in general, has a long history of use in jewelry and decorative objects. The name comes from the Sanskrit word tapas, meaning “fire,” a reference to the fiery golden topaz found in nature. Blue topaz, however, is a more modern phenomenon. Its glass-like luster and high hardness make it a versatile gemstone, suitable for a wide range of jewelry designs.
Despite its hardness (on the Mohs scale), blue topaz has strong cleavage, which means it can be prone to chipping if struck in the right direction. This has led to its recommendation for jewelry that is worn with care, such as earrings or pendants, rather than rings that are subject to daily wear.
Geological Formation and Sources
Each of the December birthstones has distinct geological origins and formation processes. Understanding how these gemstones are formed and where they are found provides insight into their rarity and value.
Tanzanite
As mentioned earlier, tanzanite is found exclusively in Tanzania. It forms in metamorphic rock under high pressure and temperature conditions. The unique combination of geological factors in the Merelani Hills allows for the development of tanzanite. The gem is closely related to zoisite and is a type of calcium aluminum silicate. Its blue-violet color is due to the presence of vanadium, which is activated through heat treatment.
Tanzanite is relatively rare, and its supply is limited due to the single-source location. This has led to its status as a highly sought-after gemstone in the jewelry market.
Turquoise
Turquoise forms in arid environments where copper-rich groundwater interacts with the mineral phosphorite. This process, known as hydration, results in the formation of turquoise in veins and nodules within the host rock. The most famous sources of turquoise are in the southwestern United States, particularly in Arizona, Nevada, and New Mexico, as well as in Iran (Persia), which has been a major source for centuries.
Turquoise is a hydrated phosphate of aluminum and copper, with the chemical formula CuAl6(PO4)4(OH)8·4H2O. It is often found with matrix, which refers to the host rock that remains within the turquoise, creating unique patterns and textures.
Blue Zircon
Zircon is a zirconium silicate that forms in igneous and metamorphic rocks. It is one of the oldest minerals on Earth and is often found in association with other gemstones such as sapphires. Zircon can occur in a wide range of colors, but blue zircon is the most popular for jewelry. The blue color is achieved through heat treatment, which alters the structure of the gem and enhances its color.
Zircon is found in many parts of the world, including Sri Lanka, Australia, Myanmar, and Brazil. Its abundance and affordability make it a popular choice for jewelry.
Blue Topaz
Topaz is a silicate mineral that forms in igneous rocks, particularly in pegmatites and rhyolites. Natural blue topaz is rare, so most of the blue topaz in jewelry is created through irradiation. The process involves exposing colorless topaz to radiation and then heating it to stabilize the blue color.
Topaz is found in several countries, including Brazil, Nigeria, and the United States. It is relatively abundant, which contributes to its affordability and popularity as a birthstone.
Gemological Properties of the December Birthstones
Understanding the gemological properties of each December birthstone is essential for both collectors and jewelers. These properties include hardness, refractive index, color, and durability, all of which affect the gem’s suitability for different types of jewelry and how it should be cared for.
| Gemstone | Mohs Hardness | Color | Chemical Formula | Refractive Index | Cleavage |
|---|---|---|---|---|---|
| Tanzanite | 6–7 | Blue to violet | Ca₂Al₃(SiO₄)(OH)₂·H₂O | 1.694–1.700 | Perfect |
| Turquoise | 5–6 | Blue to green | CuAl₆(PO₄)₄(OH)₈·4H₂O | 1.61–1.63 | Uneven |
| Blue Zircon | 6–7.5 | Blue | ZrSiO₄ | 1.92–2.01 | Good |
| Blue Topaz | 8 | Blue (treated) | Al₂SiO₄(F,OH)₄ | 1.61–1.63 | Perfect |
Tanzanite
Tanzanite has a hardness of 6–7 on the Mohs scale, which makes it relatively durable but still prone to scratches and abrasions. It is also sensitive to sudden temperature changes and can crack if exposed to very high heat. Tanzanite has perfect cleavage, meaning it can be split easily if struck in the right direction.
The gem has a refractive index of 1.694–1.700, which gives it a moderate to high brilliance. It is generally stable when exposed to light but can be damaged by strong acids like hydrochloric and hydrofluoric acid.
Turquoise
Turquoise has a hardness of 5–6 on the Mohs scale, making it relatively soft compared to other gemstones. It is also sensitive to oils, perfumes, and direct sunlight, which can cause it to fade or become brittle. Turquoise has an uneven cleavage, which means it can chip or break if subjected to impact.
The gem has a refractive index of 1.61–1.63 and is often found with matrix, which can affect its appearance and durability. Turquoise is best suited for jewelry that is worn with care, such as earrings or pendants, rather than rings.
Blue Zircon
Blue zircon has a hardness of 6–7.5 on the Mohs scale, making it a relatively durable gemstone. It is often heat-treated to produce its blue color, and some varieties may revert to their original color after prolonged exposure to bright light. Blue zircon has a refractive index of 1.92–2.01, which gives it a high brilliance and fire.
The gem has good cleavage, meaning it can be chipped or broken if struck in the right direction. It is best suited for jewelry that is worn with care, such as earrings or pendants, rather than rings that are subject to daily wear.
Blue Topaz
Blue topaz has a hardness of 8 on the Mohs scale, making it one of the hardest of the December birthstones. However, it has perfect cleavage, which means it can be easily chipped if struck in the right direction. This makes it less suitable for rings that are worn daily.
Blue topaz has a refractive index of 1.61–1.63 and is often irradiated to produce its blue color. It is generally stable when exposed to light and chemicals, though it should still be handled with care to avoid damage.
Symbolism and Metaphysical Beliefs
Each December birthstone carries its own set of symbolic and metaphysical beliefs, which have evolved over time and across cultures.
Tanzanite
Tanzanite is associated with transformation, psychic awakening, and spiritual growth. It is believed to activate the throat, third-eye, and crown chakras, allowing the wearer to access higher states of consciousness and communicate with the divine. Tanzanite is also associated with healing and protection, making it a popular choice for those seeking emotional and spiritual support.
Turquoise
Turquoise has long been regarded as a stone of protection and good fortune. In ancient Egypt, it was believed to possess many beneficial powers, such as guaranteeing health and good fortune. From the 13th century on, it was thought to protect the wearer from falling, especially off horses, and would break into several pieces at the approach of disaster. In Hindu tradition, seeing turquoise after the new moon was believed to bring great wealth.
Turquoise is also associated with wisdom, truth, and communication. It is often used in meditation and spiritual practices to enhance clarity and intuition.
Blue Zircon
Blue zircon is associated with clarity, wisdom, and the enhancement of spiritual insight. In medieval Europe, zircon was believed to have protective qualities and was used to ward off evil. It was also considered a stone of good omen and was worn by travelers for safe passage.
Blue zircon is believed to promote emotional balance and help the wearer connect with their inner self. It is also associated with the throat and heart chakras, making it a useful stone for communication and love.
Blue Topaz
Blue topaz is associated with calmness, clarity, and emotional healing. It is believed to help the wearer overcome stress, anxiety, and emotional instability. Blue topaz is also associated with wisdom and truth, making it a useful stone for those seeking to enhance their communication skills and self-expression.
In some traditions, blue topaz is also believed to promote good luck and prosperity, making it a popular choice for those seeking to manifest their goals and desires.
Care and Cleaning of the December Birthstones
Proper care and cleaning are essential for preserving the beauty and longevity of the December birthstones. Due to their varying hardness and durability, each gem requires specific handling and cleaning methods.
Tanzanite
Tanzanite has a hardness of 6–7 on the Mohs scale and is sensitive to sudden temperature changes and strong acids. It should be cleaned with warm, soapy water and a soft brush. Ultrasonic and steam cleaners are not recommended for tanzanite, as they can cause damage.
Tanzanite is best set in earrings or pendants, where it is less likely to be subjected to impact or abrasion. It is not recommended for rings that are worn daily, as it is prone to chipping and cracking.
Turquoise
Turquoise has a hardness of 5–6 on the Mohs scale and is sensitive to oils, perfumes, and direct sunlight. It should be cleaned with warm, soapy water and a soft brush. Ultrasonic and steam cleaners are not recommended for turquoise, as they can cause the gem to become brittle or fade.
Turquoise is best suited for jewelry that is worn with care, such as earrings or pendants. It is not recommended for rings or other jewelry that is subject to daily wear, as it is easily chipped or damaged.
Blue Zircon
Blue zircon has a hardness of 6–7.5 on the Mohs scale and is generally stable when exposed to light and chemicals. However, some heat-treated varieties may revert to their original color after prolonged exposure to bright light. It should be cleaned with warm, soapy water and a soft brush. Ultrasonic and steam cleaners are not recommended for blue zircon.
Blue zircon is best suited for jewelry that is worn with care, such as earrings or pendants. It is not recommended for rings that are worn daily, as it is prone to abrasion and chipping.
Blue Topaz
Blue topaz has a hardness of 8 on the Mohs scale, making it one of the hardest of the December birthstones. However, it has perfect cleavage, which means it can be easily chipped if struck in the right direction. It should be cleaned with warm, soapy water and a soft brush. Ultrasonic and steam cleaners are not recommended for blue topaz.
Blue topaz is best suited for jewelry that is worn with care, such as earrings or pendants. It is not recommended for rings that are worn daily, as it is prone to chipping and damage.
Conclusion
The December birthstones—tanzanite, turquoise, blue zircon, and blue topaz—offer a stunning array of blue hues and a rich tapestry of history, symbolism, and gemological properties. Each gemstone has its own unique story, from the ancient allure of turquoise to the modern discovery of tanzanite. Whether you are drawn to the spiritual power of tanzanite, the protective qualities of turquoise, the clarity of blue zircon, or the brilliance of blue topaz, these December birthstones are sure to captivate and inspire.
Understanding the geological origins, symbolic meanings, and care requirements of these gemstones allows you to appreciate their beauty and value in a deeper way. Whether you are a collector, a jewelry enthusiast, or simply curious about the world of gemstones, the December birthstones offer a fascinating glimpse into the intersection of nature, history, and human culture.