December is one of the few months with multiple birthstones, offering a rich palette of colors and historical significance. This month's birthstones include turquoise, zircon (particularly blue zircon), tanzanite, lapis lazuli, and blue topaz. Each of these gemstones carries unique properties, cultural symbolism, and geological characteristics that make them treasured possessions for those born in December.
This article explores the historical and cultural roots of December's birthstones, their geological properties, and their significance in modern jewelry and metaphysical traditions. The article is structured to provide a comprehensive overview of these gemstones, based on information from authoritative sources.
Introduction
December is uniquely distinguished by its array of birthstones, each with its own distinct qualities and historical relevance. The variety of options allows individuals to choose a stone that resonates with their personal preferences, spiritual beliefs, or aesthetic tastes. These gemstones include turquoise, zircon, tanzanite, lapis lazuli, and blue topaz.
While turquoise and zircon have long been considered primary December birthstones, the list has expanded to include tanzanite and blue topaz, reflecting evolving trends in gemstone appreciation and jewelry design. Each of these gemstones has a distinct color, symbolism, and geological origin, contributing to the rich cultural and spiritual significance of December's birthstones.
History and Lore
The concept of birthstones is deeply rooted in ancient traditions and religious texts. The earliest references to birthstones can be traced back to the Book of Exodus in the Bible, which lists twelve gemstones on Aaron’s breastplate, each representing a tribe of Israel. These ancient stones were believed to carry spiritual power and protection.
In the case of December, the earliest recorded gemstone associated with the month was ruby, according to some Biblical interpretations. However, by the 19th century, the list of birthstones began to evolve. The first official list of December birthstones included turquoise, a stone that has been valued since ancient times for its protective and healing properties.
In 1912, the National Association of Jewellers (now Jewellers of America) officially recognized turquoise as the primary December birthstone, with lapis lazuli as an alternative. This was later expanded in 1952 to include zircon, particularly the blue variety, due to its brilliant fire and colorful appearance. In 2002, tanzanite was added to the list, marking the first major addition to the December birthstone collection in decades.
The inclusion of multiple birthstones for December reflects the growing appreciation for gemstones with different colors, meanings, and properties. Blue topaz was also added to the list in recent years, completing a diverse collection of December birthstones that cater to a wide range of tastes and preferences.
Geological Formation and Sources
Each of December's birthstones has a unique geological origin and formation process, contributing to their distinct characteristics and rarity.
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 veins intersect with phosphorus-bearing sediments. The resulting mineral is known for its vibrant blue color, which is due to the presence of copper, and green hues, which result from iron impurities.
The most famous sources of turquoise are in the American Southwest, particularly in Nevada, Arizona, and New Mexico. Turquoise has also been found in ancient Persian mines in Iran and in China, where it was historically traded along the Silk Road.
Zircon
Zircon is a silicate mineral with the chemical formula ZrSiO₄. It is known for its high refractive index and dispersion, which give it a brilliant fire similar to that of diamonds. Zircon comes in a variety of colors, but the blue variety is especially popular as a birthstone for December.
Blue zircon is typically heat-treated to enhance its color, which can range from deep cobalt to sky blue. Zircon is found in various locations around the world, including Madagascar, Sri Lanka, and Australia. It is one of the oldest minerals on Earth, with some zircon crystals dating back over 4 billion years.
Tanzanite
Tanzanite is a blue to violet variety of the mineral zoisite, with the chemical formula Ca₂Al₃(SiO₄)(OH)₂. It is unique to the area near Mount Kilimanjaro in Tanzania, where it was first discovered in 1967. Tanzanite is known for its pleochroism, a property that allows it to display different colors depending on the angle of light.
The formation of tanzanite requires a specific set of geological conditions, including high pressure and the presence of vanadium, which contributes to its blue coloration. Due to its limited source, tanzanite is considered a rare and valuable gemstone.
Lapis Lazuli
Lapis lazuli is a metamorphic rock composed primarily of lazurite, with smaller amounts of other minerals such as pyrite and calcite. Its deep blue color is due to the presence of sulfur-rich lazurite crystals. Lapis lazuli has been used as a gemstone and ornamental stone for thousands of years.
The most famous source of lapis lazuli is the Badakhshan region in Afghanistan, where it has been mined for over 6,000 years. It was highly valued in ancient Egypt and Mesopotamia, where it was used in jewelry, amulets, and decorative objects.
Blue Topaz
Blue topaz is a silicate mineral with the chemical formula Al₂SiO₄(F,OH)₂. It is a colorless form of topaz that is treated with irradiation or heat to produce a range of blue colors, from pale sky blue to deep blue. Blue topaz is relatively abundant and affordable, making it a popular choice for jewelry.
Topaz is found in various parts of the world, including Brazil, Mexico, and the United States. It forms in igneous rocks, particularly in pegmatites and rhyolites, where it can grow into large, well-formed crystals.
Gemological Properties
Each of December's birthstones has distinct physical and optical properties that make them valuable in jewelry and gemstone collections.
| Gemstone | Color | Hardness (Mohs) | Refractive Index | Cleavage | Specific Gravity |
|---|---|---|---|---|---|
| Turquoise | Blue, green | 5–6 | 1.61–1.65 | None | 2.7–2.9 |
| Zircon | Blue, colorless, yellow | 6.5–7.5 | 1.92–2.01 | Perfect | 4.6–4.8 |
| Tanzanite | Blue, violet | 6–7 | 1.694–1.701 | Perfect | 3.1–3.4 |
| Lapis Lazuli | Blue, gold | 5–6 | 1.65–1.70 | None | 2.4–2.9 |
| Blue Topaz | Blue | 8 | 1.61–1.63 | Perfect | 3.5–3.55 |
Turquoise
Turquoise has a hardness of 5–6 on the Mohs scale, making it relatively soft and susceptible to scratches. It has a refractive index of 1.61–1.65 and does not have cleavage, which makes it less prone to breaking. Its specific gravity ranges from 2.7 to 2.9, indicating a moderate density.
Zircon
Zircon is a relatively hard gemstone with a hardness of 6.5–7.5 on the Mohs scale. It has a high refractive index of 1.92–2.01, which contributes to its brilliance and fire. Zircon has perfect cleavage, which means it can be chipped or broken if struck at the right angle. Its specific gravity is 4.6–4.8, indicating a high density.
Tanzanite
Tanzanite has a hardness of 6–7 on the Mohs scale. It has a refractive index of 1.694–1.701 and exhibits perfect cleavage, making it somewhat fragile. Its specific gravity is 3.1–3.4, indicating a moderate density.
Lapis Lazuli
Lapis lazuli has a hardness of 5–6 on the Mohs scale. It has a refractive index of 1.65–1.70 and does not have cleavage. Its specific gravity is 2.4–2.9, indicating a low to moderate density.
Blue Topaz
Blue topaz has a hardness of 8 on the Mohs scale, making it one of the hardest December birthstones. It has a refractive index of 1.61–1.63 and exhibits perfect cleavage. Its specific gravity is 3.5–3.55, indicating a moderate density.
Symbolism and Metaphysical Beliefs
December's birthstones have been associated with various symbolic meanings and metaphysical properties across different cultures and eras.
Turquoise
Turquoise has long been considered a protective stone, believed to ward off evil and promote good fortune. In ancient Egypt, it was used in amulets and funerary objects to protect the dead in the afterlife. In Native American cultures, turquoise is associated with healing, spiritual connection, and protection.
Zircon
Zircon is often regarded as a stone of transformation and spiritual awakening. It is believed to enhance intuition, clarity, and insight. Blue zircon, in particular, is associated with communication, truth, and emotional healing.
Tanzanite
Tanzanite is believed to promote emotional healing, balance, and spiritual growth. It is associated with the heart and throat chakras and is said to enhance self-expression, compassion, and empathy. Due to its rarity and beauty, it is also considered a stone of luxury and individuality.
Lapis Lazuli
Lapis lazuli is a stone of wisdom, truth, and spiritual enlightenment. It has been used in ancient Egyptian and Mesopotamian cultures as a symbol of royalty and divine power. In modern metaphysical traditions, it is believed to enhance intellectual ability, self-awareness, and emotional stability.
Blue Topaz
Blue topaz is associated with calmness, clarity, and emotional healing. It is believed to soothe the mind, reduce stress, and enhance creativity. It is also considered a stone of good fortune and positive change.
Care and Cleaning
Proper care and maintenance are essential to preserving the beauty and longevity of December's birthstones.
Turquoise
Turquoise is sensitive to heat, chemicals, and prolonged exposure to sunlight, which can cause it to fade or become brittle. It should be stored in a cool, dry place and cleaned with a soft, damp cloth. Avoid using harsh chemicals or ultrasonic cleaners.
Zircon
Zircon should be cleaned with warm, soapy water and a soft cloth. It is sensitive to heat and should be kept away from high temperatures. Due to its perfect cleavage, it should be handled with care to avoid chipping or breaking.
Tanzanite
Tanzanite should be cleaned with a mild detergent and a soft cloth. Avoid exposure to heat and direct sunlight, as these can cause fading. Due to its perfect cleavage, it should be handled with care.
Lapis Lazuli
Lapis lazuli should be cleaned with a soft, damp cloth and mild detergent. It is sensitive to heat and chemicals and should be stored in a cool, dry place. Avoid exposure to acidic substances, which can damage the stone.
Blue Topaz
Blue topaz is relatively durable and can be cleaned with warm, soapy water and a soft cloth. It can also be cleaned with an ultrasonic cleaner. Due to its perfect cleavage, it should be handled with care to avoid chipping.
Conclusion
December's birthstones offer a rich and diverse selection of gemstones, each with its own unique properties, history, and symbolism. From the ancient and protective turquoise to the rare and radiant tanzanite, these stones have been cherished for centuries for their beauty and spiritual significance.
Whether chosen for their historical ties, geological rarity, or metaphysical properties, December's birthstones provide a meaningful and elegant way to celebrate the month of December. Their variety ensures that there is a perfect stone for every individual, reflecting the unique qualities and preferences of those born in this month.
By understanding the history, properties, and care requirements of these gemstones, individuals can make informed choices when selecting or wearing December's birthstones. These stones are not just decorative objects but also connections to the past, symbols of personal identity, and enduring reminders of the beauty and complexity of the natural world.