December is unique among the calendar months, boasting not one, but three recognized birthstones: tanzanite, turquoise, and zircon. Each of these gems presents a distinctive shade of blue, mirroring the cool tones of the winter season, and offering a range of options for those born in the twelfth month of the year. While turquoise holds the longest history as a December birthstone, tanzanite represents a more recent discovery, unearthed in Tanzania in 1967. These gemstones are associated with meanings of wisdom, protection, and new beginnings, providing December-born individuals with a variety of choices to express their personal style and beliefs.
A History of December’s Gems
Turquoise has a particularly long and storied past, prized by cultures worldwide for over 5,000 years. Its use dates back millennia, with significant finds and mining operations established in the Nishapur district of Iran more than a thousand years ago. The most highly regarded turquoise from this region, characterized by an even, intense blue hue, earned descriptive terms like “robin’s egg blue,” “sky blue,” and “Persian blue,” which are still used today to denote this quality regardless of the stone’s origin.
More recently, turquoise production has shifted, with New Mexico being a major source until the 1920s. Today, Arizona and Nevada are prominent producers within the United States, with mines like Dry Creek, Easter Blue, Emerald Valley, and Fox contributing to the supply. China currently leads global turquoise production, primarily from the Hubei Province.
Tanzanite, in contrast, is a newcomer to the world of gemstones. Discovered in Tanzania in 1967, it quickly gained popularity for its captivating blue-violet color. While it lacks the extensive lore associated with older stones like rubies or emeralds, tanzanite has rapidly acquired its own symbolism and appeal. It was initially named ‘Blue Zoisite’ before being renamed Tanzanite in honor of its country of origin.
Zircon also has a long history, though its association with December is more recent. It is found alongside sapphire in locations like Sri Lanka, Australia, Myanmar, Vietnam, and Cambodia.
Geological Formation and Sources
Turquoise is a semi-translucent to opaque gem, often exhibiting veins of matrix – remnants of the rock in which it formed – running through it. Its formation occurs relatively close to the Earth’s surface, often in arid regions. Significant sources include Iran, the United States (Arizona and Nevada), and China (Hubei Province).
Tanzanite is remarkably unique in its geographic origin. It is found exclusively in Tanzania, a relatively small area near the Mererani Hills. This limited source contributes to its rarity and value. It is often located near sapphire deposits.
Zircon, ranging from 6 to 7.5 on the Mohs scale of hardness, is found in a variety of geological settings. It can occur in metamorphic and igneous rocks, and is often associated with alluvial deposits. Sources include Sri Lanka, Australia, Myanmar, Vietnam, and Cambodia.
Gemological Properties
The three December birthstones exhibit distinct gemological properties. Turquoise, ranging from blue to green, is a hydrated phosphate of copper and aluminum. Its color is influenced by the presence of copper, while aluminum contributes to its structure.
Tanzanite, a calcium aluminum silicate, displays a mesmerizing array of hues, from deep sapphire blue to vibrant violet-blue. A notable characteristic of tanzanite is pleochroism – the ability to display different colors when viewed from different angles. This phenomenon reveals varying shades of blue, violet, and red within the gem.
Zircon, a zirconium silicate, comes in a wide spectrum of colors, including blue, golden, red, and clear. The blue varieties are particularly popular as December birthstones. Zircon can be heat-treated to enhance its color, producing the vibrant blues and colorless stones often seen in jewelry.
Here's a table summarizing key properties:
| Gemstone | Chemical Formula | Color(s) | Hardness (Mohs) | Notable Properties |
|---|---|---|---|---|
| Turquoise | Hydrated Phosphate of Copper and Aluminum | Blue to Green | 5-6 | Often contains matrix |
| Tanzanite | Calcium Aluminum Silicate | Blue, Violet-Blue, Reddish | 6.5-7 | Pleochroism |
| Zircon | Zirconium Silicate | Blue, Golden, Red, Clear | 6-7.5 | Can be heat-treated |
Symbolism and Metaphysical Beliefs
Throughout history, these December birthstones have been attributed with various symbolic meanings and metaphysical properties. Turquoise has long been revered for its spiritual and healing qualities by ancient cultures.
Tanzanite is believed to possess high-vibration healing energy and is often considered a stone of transformation, linked to spiritual awareness and manifestation. It is associated with wisdom, peace, and inner strength, and is a popular gift for 24th wedding anniversaries. Some believe it can activate the throat, third-eye, and crown chakras, enhancing psychic abilities and communication with higher dimensions.
Zircon is associated with prosperity and wisdom.
Care and Cleaning
Proper care is essential to maintain the beauty of these December birthstones. Zircon, with a hardness of 6 to 7.5 on the Mohs scale, is susceptible to abrasion and should be protected from rough wear. Avoid wearing it during activities like gardening, sports, or dishwashing. Cleaning can be done with a soft brush and mild soap in warm water; ultrasonic and steam cleaners are not recommended.
Turquoise, being relatively soft (5-6 on the Mohs scale), requires gentle handling. Avoid harsh chemicals and abrasive cleaners. Cleaning should be done with a soft cloth and mild soap.
Tanzanite, with a hardness of 6.5-7, is generally stable but can be affected by prolonged exposure to bright light, potentially causing some heat-treated stones to revert to their original color. It is best to store tanzanite away from direct sunlight. Cleaning can be done with a soft brush, mild soap, and warm water.
Conclusion
The December birthstones – tanzanite, turquoise, and zircon – offer a captivating range of colors, histories, and symbolic meanings. From the ancient lore surrounding turquoise to the recent discovery of tanzanite and the enduring appeal of zircon, these gems provide a wealth of options for those born in the final month of the year. Each stone possesses unique geological origins and gemological properties, making them not only beautiful adornments but also fascinating subjects of study for gemstone enthusiasts and professionals alike. The choice between these three gems ultimately comes down to personal preference, allowing individuals to select a birthstone that resonates with their style, beliefs, and connection to the winter season.