December, the final month of the year, is richly adorned with a unique selection of birthstones that reflect its wintry ambiance and historical depth. Unlike months that are associated with a single gemstone, December is distinguished by a collection of five gemstones, each with its own color, symbolic meaning, and geological origin. These include Blue Zircon, Tanzanite, Blue Topaz, Lapis Lazuli, and Turquoise. The diversity of December’s birthstones offers wearers a range of aesthetic and cultural options, making it one of the most intriguing months in the birthstone calendar.
This article delves into the rich tapestry of December’s birthstones, exploring their historical significance, gemological properties, and cultural symbolism. It also covers the modern evolution of the birthstone list, the reasons behind the inclusion of multiple gemstones, and practical care tips for maintaining these precious stones.
History and Lore
The tradition of associating gemstones with specific months dates back centuries, with roots in ancient civilizations and biblical references. The earliest known records of birthstones appear in the Book of Exodus, where 12 stones were listed as part of the High Priest’s breastplate. However, these ancient stones differ significantly from today’s modern birthstones, and the December gemstone in this list was ruby.
Over time, the birthstone traditions evolved. By the 19th century, birthstone lists had shifted to align more closely with contemporary cultural and commercial practices. The birthstone for December began its journey in the 1870s, when the gemstone Turquoise was first designated as the December birthstone in a pamphlet published by Tiffany & Co. titled "Gregorian Birthstone Poems."
In 1912, the National Association of Jewellers (now Jewellers of America) recognized both Turquoise and Lapis Lazuli as the December birthstones. Then, in 1952, Zircon, particularly Blue Zircon, was added to the list by the Jewelry Industry Council of America. This was followed by the inclusion of Tanzanite in 2002, marking the final expansion of the December birthstone lineup.
The inclusion of multiple gemstones for December reflects the evolving nature of gemstone appreciation and the desire to provide a range of options for different tastes, budgets, and cultural associations. Turquoise and Zircon have long been considered the primary December birthstones, while Tanzanite, Lapis Lazuli, and Blue Topaz were added later to reflect the diversity of gemstone colors and meanings.
Geological Formation and Sources
Understanding the geological origins of December’s birthstones provides insight into their rarity, beauty, and value. Each gemstone forms under unique conditions and is found in specific locations around the world.
Blue Zircon
Zircon is a mineral that has existed on Earth for billions of years and is among the oldest known minerals. Blue Zircon, in particular, is created through a process called irradiation and heat treatment, which alters the color of the zircon crystal. While zircon is found in various parts of the world, including Thailand, Cambodia, and Brazil, Blue Zircon is most commonly associated with Australia and Madagascar.
Zircon is known for its high refractive index and brilliant fire, often compared to diamonds. Its hardness on the Mohs scale ranges from 6.5 to 7.5, making it relatively durable for jewelry use. However, because zircon can have cleavage planes, it requires careful handling during cutting and setting.
Tanzanite
Tanzanite is a rare gemstone that is only found in one location in the world: the Merelani Hills near Mount Kilimanjaro in Tanzania. This gemstone was first discovered in the 1960s and has since become one of the most sought-after stones in the jewelry industry. Tanzanite is a variety of the mineral zoisite and is known for its striking blue to violet color, which is enhanced through heat treatment.
Tanzanite has a hardness of 6 to 6.5 on the Mohs scale, which is relatively soft for a gemstone. This makes it more susceptible to scratches and damage, especially when worn in everyday jewelry. The limited supply and unique color of Tanzanite contribute to its high value and exclusivity.
Blue Topaz
Blue Topaz is a popular choice for December due to its affordability and beautiful color. Naturally occurring blue topaz is rare, and most of the blue topaz available in the market is created through irradiation and heat treatment. The gemstone is primarily found in Brazil, but it is also mined in the United States, Mexico, and Nigeria.
Topaz is one of the hardest gemstones, with a hardness of 8 on the Mohs scale. It is known for its clarity and brilliance, making it an excellent choice for a wide range of jewelry designs.
Lapis Lazuli
Lapis Lazuli is a metamorphic rock composed mainly of lazurite, with smaller amounts of pyrite and calcite. It is best known for its deep blue color and golden flecks of pyrite. The finest lapis lazuli is found in Afghanistan, where it has been mined for thousands of years. Other sources include Russia, Argentina, and the United States.
Lapis lazuli has a hardness of 5 to 6 on the Mohs scale, making it relatively soft and prone to scratches. It is often used in carvings, beads, and cabochon cuts rather than in faceted jewelry.
Turquoise
Turquoise is a hydrated phosphate of aluminum and copper, and it is known for its characteristic blue-green color. It is formed in arid regions where copper-rich water percolates through rocks and deposits turquoise in cavities. The finest turquoise is found in Iran, China, and the United States, particularly in the Southwest.
Turquoise has a hardness of 5 to 6 on the Mohs scale, and it is often treated with stabilizing agents to enhance its durability. It is highly valued for its historical significance and cultural associations with protection and good fortune.
Gemological Properties
Each of December’s birthstones possesses unique gemological properties that contribute to its beauty, durability, and appeal.
| Gemstone | Color | Hardness (Mohs) | Chemical Formula | Refractive Index | Transparency | Treatments Commonly Used |
|---|---|---|---|---|---|---|
| Blue Zircon | Blue | 6.5–7.5 | ZrSiO₄ | 1.92–2.01 | Transparent | Irradiation, Heat |
| Tanzanite | Blue to Violet | 6–6.5 | Ca₂Al₃(SiO₄)₃(OH) | 1.69–1.70 | Transparent | Heat |
| Blue Topaz | Blue | 8 | Al₂SiO₆ | 1.61–1.63 | Transparent | Irradiation, Heat |
| Lapis Lazuli | Deep Blue with Pyrite Flecks | 5–6 | Lazurite, Pyrite, Calcite | Varies | Opaque | None |
| Turquoise | Blue-Green | 5–6 | CuAl₆(PO₄)₄(OH)₈·4H₂O | 1.61–1.65 | Translucent | Stabilization, Enhancement |
These properties make each gemstone suitable for different types of jewelry and settings. For example, the high hardness and brilliance of Blue Topaz and Zircon make them ideal for engagement rings and other statement pieces, while the softer and more colorful nature of Lapis Lazuli and Turquoise is better suited for pendants, earrings, and carved pieces.
Symbolism and Metaphysical Beliefs
The symbolic meanings and metaphysical properties of December’s birthstones have been cherished across cultures and eras.
Blue Zircon
Blue Zircon is often associated with clarity, truth, and spiritual awakening. It is believed to enhance intuition, promote inner peace, and help the wearer connect with their higher self. In some traditions, zircon is also seen as a stone of protection and is used to ward off negative energies.
Tanzanite
Tanzanite is known as a stone of transformation and emotional healing. It is believed to help individuals process complex emotions, release old patterns, and embrace change. Due to its rarity, Tanzanite is also associated with exclusivity and the idea of seizing unique opportunities in life.
Blue Topaz
Blue Topaz is often linked to calmness, serenity, and emotional balance. It is believed to help reduce stress, enhance communication, and promote a sense of peace. Blue Topaz is also associated with wisdom and is thought to aid in decision-making and mental clarity.
Lapis Lazuli
Lapis Lazuli has long been associated with wisdom, truth, and enlightenment. In ancient times, it was considered a stone of the gods and was used in royal regalia and sacred artifacts. It is believed to enhance intellectual abilities, stimulate creativity, and promote spiritual growth.
Turquoise
Turquoise is one of the most revered gemstones in history and is often regarded as a stone of protection and good fortune. It is believed to bring positive energy, promote healing, and ward off negative influences. In many cultures, turquoise is also associated with love, friendship, and the ability to attract abundance.
Care and Cleaning
Proper care and maintenance are essential to preserving the beauty and longevity of December’s birthstones. Due to their varying hardness levels and susceptibility to damage, each gemstone requires specific care instructions.
- Blue Zircon: Avoid exposing Blue Zircon to harsh chemicals or extreme temperatures. Clean it with warm, soapy water and a soft cloth. Avoid ultrasonic cleaners if the stone has any fractures or inclusions.
- Tanzanite: Tanzanite is relatively soft and should be cleaned gently with a mild soap solution. Avoid ultrasonic or steam cleaners, as these can cause damage to the stone.
- Blue Topaz: Blue Topaz is durable and can be cleaned using ultrasonic or steam cleaners. Avoid exposing it to harsh chemicals, as these can affect the color.
- Lapis Lazuli: Lapis Lazuli is a soft stone that requires careful handling. It should be cleaned with a damp cloth and mild soap. Avoid using harsh chemicals or abrasive materials.
- Turquoise: Turquoise is sensitive to water and should be cleaned gently with a dry cloth. Avoid exposing it to water or chemicals, as these can cause discoloration or damage.
By following these care instructions, December’s birthstones can retain their brilliance and beauty for generations to come.
Conclusion
December’s birthstones—Blue Zircon, Tanzanite, Blue Topaz, Lapis Lazuli, and Turquoise—offer a stunning array of colors, histories, and meanings. These gemstones reflect the rich cultural and geological heritage of the December month and provide wearers with a unique way to express their individuality.
From the ancient traditions of lapis lazuli and turquoise to the modern additions of tanzanite and blue zircon, the December birthstone list showcases the evolving nature of gemstone appreciation. Whether valued for their beauty, symbolism, or rarity, these gemstones continue to captivate gemstone enthusiasts, jewelry buyers, and students of gemology.
By understanding the history, properties, and care of these gemstones, individuals can make informed decisions when selecting December birthstone jewelry and ensure that these precious stones remain a cherished part of their personal and cultural heritage.