December is a unique month in the world of birthstones, distinguished by having not one, but four recognized gems: turquoise, tanzanite, zircon, and blue topaz. These stones, predominantly showcasing shades of blue, represent the cool tones of winter and have been treasured for centuries for their beauty, rarity, and the meanings they carry. The addition of multiple birthstones reflects a historical evolution in birthstone lists, responding to expanding gemstone markets and consumer preferences. While earlier lists designated ruby as a December stone, the modern selection offers a wider range of options, each with its own distinct history and appeal.
History and Lore
The history of December birthstones is a tapestry woven with ancient traditions and more recent discoveries. Turquoise stands out as the most ancient of these gems, with a history stretching back millennia. Ancient Egyptians revered turquoise, believing it to be a gift from the gods and incorporating it into elaborate jewelry, notably the funerary mask of King Tut. Its significance extended across cultures, appearing in imperial decorations in China, where it symbolized immortality, and holding deep spiritual meaning for Indigenous cultures in the Americas. In Tibet, turquoise is even considered a “national treasure.”
Zircon, while also possessing a long history, experienced a shift in prominence. It was added to the December birthstone list in 1952, expanding the options available. The relatively recent addition of tanzanite, in 2002, reflects its discovery in the late 20th century and its subsequent rise in popularity. Blue topaz, another member of the December quartet, has a history rooted in ancient civilizations, though its association specifically with December is a more recent development.
The evolution of the December birthstone list demonstrates a changing understanding of gemstones and their cultural significance. The earliest lists, inspired by Biblical references, initially featured ruby for December. Over time, through publications like Tiffany & Co.’s “Gregorian Birthstone Poems” in 1870 and subsequent revisions by organizations like the National Association of Jewellers and the Jewelry Industry Council of America, the list expanded to include the stones celebrated today.
Geological Formation and Sources
The geological origins of these December birthstones are as diverse as their histories. Turquoise is a hydrated phosphate of copper and aluminum, forming in relatively dry, arid environments. It is often found in association with copper deposits, and significant sources include the southwestern United States, particularly Arizona and New Mexico, as well as Iran and China.
Tanzanite, a relatively recent discovery, is a blue-violet variety of the mineral zoisite. It is found in a very limited geographical area: the Merelani Hills of northern Tanzania, hence its name. This restricted source contributes to its rarity and value.
Zircon, a zirconium silicate, forms in igneous rocks and metamorphic rocks. It occurs in a wide range of colors, but the blue varieties are particularly prized as December birthstones. Sources include Cambodia, Sri Lanka, and Myanmar.
Blue topaz is a variety of topaz that has been irradiated to enhance its blue color. Topaz itself forms in igneous rocks and is found in Brazil, Nigeria, and Russia, among other locations. The irradiation process is a common practice to create the desired blue hue for the birthstone market.
Gemological Properties
Each of the December birthstones possesses unique gemological properties that contribute to its beauty and desirability.
Turquoise: Its color ranges from sky blue to greenish-blue, often with matrix patterns (veins of other minerals). Turquoise typically lacks strong brilliance and is relatively soft, with a Mohs hardness of 5-6.
Tanzanite: This gemstone exhibits a trichroism, meaning it displays three different colors (blue, violet, and burgundy) depending on the viewing angle. Its hardness is 6.5-7 on the Mohs scale.
Zircon: Blue zircon is known for its strong “fire,” or dispersion, which gives it a brilliant sparkle. It has a hardness of 6.5-7.5 on the Mohs scale. It is important to note that zircon is sometimes confused with cubic zirconia, a synthetic diamond simulant.
Blue Topaz: This gemstone is known for its clarity and affordability. It has a hardness of 8 on the Mohs scale, making it relatively durable.
The following table summarizes key gemological properties:
| Gemstone | Chemical Composition | Hardness (Mohs) | Color(s) | Notable Properties |
|---|---|---|---|---|
| Turquoise | Hydrated Phosphate of Copper and Aluminum | 5-6 | Sky Blue to Greenish-Blue | Matrix patterns, relatively soft |
| Tanzanite | Calcium Aluminum Silicate (Zoisite) | 6.5-7 | Blue, Violet, Burgundy | Trichroism |
| Zircon | Zirconium Silicate | 6.5-7.5 | Blue | Strong fire |
| Blue Topaz | Aluminum Silicate Fluoride | 8 | Blue | Clarity, durability |
Symbolism and Metaphysical Beliefs
Throughout history, each of these December birthstones has been attributed with various symbolic meanings and metaphysical properties. Turquoise has long been associated with friendship, good fortune, health, protection, and peace. Native American cultures particularly valued turquoise for its spiritual and protective qualities.
Tanzanite is believed to promote communication, intuition, and spiritual awareness. It is often associated with transformation and positive energy.
Zircon is thought to enhance wisdom, honor, and prosperity. Blue zircon, in particular, is believed to calm the emotions and promote restful sleep.
Blue topaz is associated with communication, loyalty, and clarity of thought. It is believed to promote honesty and openness.
These symbolic associations contribute to the enduring appeal of December birthstones, making them meaningful gifts and cherished possessions.
Care and Cleaning
Proper care is essential to maintain the beauty of December birthstones. Turquoise, being relatively soft, is susceptible to scratches and should be protected from harsh impacts. It is best cleaned with a soft cloth and mild soap and water. Avoid ultrasonic cleaners and harsh chemicals.
Tanzanite is also relatively delicate and should be handled with care. It can be cleaned with warm, soapy water and a soft brush. Avoid sudden temperature changes.
Zircon and blue topaz are more durable but should still be protected from scratches and impacts. They can be cleaned with warm, soapy water and a soft brush. Ultrasonic cleaners can be used with caution.
Regular cleaning and proper storage will help ensure that these December birthstones retain their brilliance and beauty for years to come.
Conclusion
The December birthstones – turquoise, tanzanite, zircon, and blue topaz – represent a diverse and captivating collection of gems. From the ancient lore surrounding turquoise to the modern appeal of tanzanite, each stone offers a unique history, symbolism, and beauty. The expansion of the December birthstone list reflects a growing appreciation for the variety and significance of gemstones, providing individuals born in this month with a wider range of options to choose from. Whether seeking a meaningful gift or a personal talisman, these radiant gems offer a connection to both the natural world and the rich tapestry of human history.