December’s Trio: Tanzanite, Turquoise, and Zircon – A Celebration of Color and Lore

December is a unique month in the world of birthstones, distinguished by not one, but three designated gems: tanzanite, turquoise, and zircon. These stones, each possessing a distinct history, geological origin, and symbolic meaning, offer a diverse palette of color and resonate with individuals born in the final month of the calendar year. This article will delve into the fascinating world of these December birthstones, exploring their historical use, geological formation, gemological properties, and cultural significance.

History and Lore

The tradition of associating specific gemstones with months of the year dates back to ancient times, rooted in biblical and cultural beliefs. However, the modern birthstone list has undergone numerous revisions. Initially, ruby was designated for December, as reflected in early biblical gemstone lists. The evolution of December’s birthstones is particularly notable. In 1870, Tiffany & Co.’s “Gregorian Birthstone Poems” pamphlet listed turquoise as the stone for December. By 1912, the National Association of Jewellers (now Jewellers of America) recognized turquoise as the primary stone, with lapis lazuli as an alternative. Zircon was added to the list in 1952 by the Jewelry Industry Council of America, and tanzanite was the most recent addition in 2002. This expansion reflects a desire to offer a wider range of choices in color, price, and personal meaning.

Turquoise boasts a long and storied history, revered by ancient civilizations for its beauty and perceived protective qualities. Zircon, one of the oldest minerals on Earth, has captivated gem enthusiasts for centuries with its dazzling fire. Tanzanite, in contrast, is a relatively recent discovery, first identified in 1967. Its unique origin and captivating color quickly established it as a sought-after gemstone.

Geological Formation and Sources

Each of these December birthstones originates through distinct geological processes and is found in specific locations around the globe.

Tanzanite is exceptionally rare, found exclusively in the Merelani Hills of Tanzania, near Mount Kilimanjaro. Its formation is linked to the complex geological activity of the region. The gemstone was discovered by a Maasai tribesman who noticed unusual blue-violet crystals exposed on the surface.

Turquoise, a hydrated phosphate of copper and aluminum, forms in arid regions through a process of weathering of copper-rich rocks. Significant sources of turquoise include the southwestern United States, Iran, and China. The stone has been mined for thousands of years, with evidence of its use dating back to ancient Egypt and Persia.

Zircon is found in a variety of geological settings, including igneous, metamorphic, and sedimentary rocks. Major sources of zircon include Sri Lanka, Cambodia, Vietnam, and Australia. Its durability and resistance to weathering make it a common mineral in alluvial deposits. While zircon comes in a rainbow of colors, blue zircon is particularly favored as a December birthstone.

Gemological Properties

Each of these gemstones possesses unique gemological properties that contribute to its beauty and value.

Tanzanite exhibits a striking trichroism, displaying three different colors – blue, violet, and burgundy – depending on the viewing angle. This property, combined with its brilliance and clarity, makes it a popular choice for jewelry. Heat treatment is commonly used to enhance tanzanite’s color and clarity, a practice widely accepted within the gem trade.

Turquoise is characterized by its opaque nature and distinctive blue-green color, though shades can vary depending on the presence of other minerals. Its color is derived from copper, while aluminum and phosphate contribute to its structure.

Zircon is known for its high refractive index and strong dispersion, resulting in exceptional brilliance and “fire.” It occurs in a wide range of colors, including brown, red, orange, yellow, green, and blue. Blue zircon is the most commonly associated with December, and its clarity and color are highly valued.

Here's a comparative table summarizing key gemological properties:

Property	Tanzanite	Turquoise	Zircon
Chemical Formula	Ca₂Al₃(SiO₄)₃(OH)	CuAl₆(PO₄)₄(OH)₈·4H₂O	ZrSiO₄
Color	Blue, Violet	Blue-Green	Colorless, Blue, Brown, Red
Hardness (Mohs)	6.5 - 7	5 - 6	6.5 - 7.5
Transparency	Transparent	Opaque	Transparent
Refractive Index	1.482 - 1.488	1.61 - 1.62	1.81 - 2.02

Symbolism and Metaphysical Beliefs

Throughout history, each of these December birthstones has been attributed with specific symbolic meanings and metaphysical properties.

Turquoise is believed to stimulate wisdom, trust, and understanding. It is also associated with strengthening the immune system, aiding in nutrient absorption, and providing protection.

Zircon is thought to promote honor, self-esteem, and clarity. It is also believed to relieve pain and inflammation, protect against nightmares, and bring prosperity and love.

Tanzanite is associated with enhancing intuition and psychic abilities, promoting spiritual growth and inner peace, and balancing the energies of the mind, body, and spirit. It is also believed to foster compassion, gentleness, and empathy.

Combining the energies of all three December birthstones is believed to bring a wealth of positive effects to those born in this month, complementing each other and providing benefits spanning the physical, emotional, and spiritual realms.

Care and Cleaning

Proper care is essential to maintain the beauty and luster of these December birthstones.

Tanzanite, with a hardness of 6.5 to 7 on the Mohs scale, is relatively delicate and susceptible to scratches. It should be cleaned with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and harsh chemicals.

Turquoise, being a softer stone (5-6 on the Mohs scale), requires gentle handling. It should be cleaned with a soft cloth and mild soap. Avoid prolonged exposure to sunlight and harsh chemicals, as these can affect its color.

Zircon, with a hardness of 6.5 to 7.5, is more durable than tanzanite and turquoise. It can be cleaned with warm, soapy water and a soft brush. However, avoid sudden temperature changes, as these can cause fractures.

Conclusion

December’s trio of birthstones – tanzanite, turquoise, and zircon – represent a captivating blend of history, geology, and symbolism. From the ancient lore surrounding turquoise and zircon to the recent discovery of tanzanite, these gemstones offer a diverse range of colors and properties that appeal to a wide spectrum of tastes. Whether chosen for their aesthetic beauty, perceived metaphysical benefits, or historical significance, these December birthstones continue to hold a special place in the hearts of gem enthusiasts and jewelry lovers alike. Their unique origins and enduring appeal solidify their status as treasured gems for those born in the final month of the year.