December is a unique month in the world of birthstones, celebrated with not one, but three distinct gems: Turquoise, Blue Topaz, and Tanzanite. These stones, each possessing a captivating blue hue and a rich history, offer a diverse range of options for those seeking meaningful jewelry or simply an appreciation for the earth’s treasures. While traditional birthstones for December also include Lapis Lazuli and Blue Zircon, this article will focus on the properties, history, and significance of Turquoise, Blue Topaz, and Tanzanite, as detailed in available sources.
A Historical Tapestry
The history of December’s birthstones spans millennia. Turquoise, arguably the oldest of the three, has been prized by cultures for centuries. The Aztecs mined turquoise in areas now known as New Mexico, and significant deposits are still found in Arizona, California, and Nevada. For centuries, the most valuable turquoise originated from Iran (Persia), though modern specimens from the southwestern United States now compete in quality. Its use dates back to ancient times, symbolizing friendship, tranquility, and protection.
Blue Topaz, while also possessing a long history, has a more varied lineage. Topaz deposits have been found across the globe, including Brazil, Afghanistan, Australia, and the United Kingdom, with natural light-blue topaz specifically noted in Northern Ireland. The name “topaz” itself may originate from the Sanskrit word tapas, meaning “fire,” or from the Greek topazos. Throughout history, topaz has been believed to bestow strength, dispel anger, and even ward off magic spells.
Tanzanite, in contrast, is a relatively recent discovery. Found in Tanzania in the 20th century, it quickly gained popularity for its deep, rich violet-blue hue. This makes it a modern addition to the birthstone list, representing a more contemporary choice for December babies.
Geological Origins and Global Sources
The formation and sourcing of these gemstones differ significantly. Turquoise is formed in relatively shallow deposits, often near copper mines, through a chemical reaction between water, copper ions, and aluminum phosphates. This process results in a hydrated copper aluminum phosphate mineral.
Blue Topaz, a silicate mineral containing aluminum and fluorine, forms in igneous rocks. Deposits are found in a wide range of locations, including Brazil, Afghanistan, Australia, Myanmar (Burma), China, and several European countries. The blue color often seen in commercially available topaz is achieved through irradiation and heating of colorless topaz, a permanent treatment that enhances its vibrancy.
Tanzanite, a variety of the mineral zoisite, is found in a very limited geographical area: the Merelani Hills of northern Tanzania. This singular origin contributes to its rarity and value. The gemstone’s unique trichroism – displaying three different colors depending on the viewing angle – is a result of its complex chemical composition and crystal structure.
Gemological Properties: A Comparative Overview
Each of these December birthstones possesses distinct gemological properties.
| Property | Turquoise | Blue Topaz | Tanzanite |
|---|---|---|---|
| Chemical Formula | CuAl6(PO4)4(OH)8·4H2O | Al2SiO4(OH,F)2 | Ca2Al3(SiO4)3(OH) |
| Color | Blue-green | Blue | Violet-blue |
| Hardness (Mohs) | 5-6 | 8 | 6.5-7 |
| Transparency | Opaque | Transparent | Transparent |
| Specific Gravity | 2.60-2.80 | 3.49-3.57 | 3.35-3.49 |
Turquoise, with a Mohs hardness of 5-6, is relatively soft compared to the other two. This makes it susceptible to scratching and requires careful handling. It is typically opaque, meaning light cannot pass through it. Often, turquoise is dyed and stabilized with resins to enhance its color and durability.
Blue Topaz, boasting a hardness of 8 on the Mohs scale, is a significantly more durable gemstone. Its transparency allows for brilliant cuts and exceptional sparkle. The treatment process to achieve the vibrant blue color is permanent, making it a stable and long-lasting gem.
Tanzanite, with a hardness of 6.5-7, falls between turquoise and topaz in terms of durability. Its transparency and trichroism contribute to its unique visual appeal. The gemstone’s pleochroism means that it can display different colors when viewed from different angles, adding to its allure.
Symbolism and Metaphysical Beliefs
Throughout history, each of these gemstones has been imbued with symbolic meaning. Turquoise has long been associated with friendship, tranquility, and protection. It was believed to bring good fortune and ward off negative energy.
Blue Topaz is often linked to communication, honesty, and clarity of thought. Ancient Greeks believed it provided strength, while Europeans thought it could dispel anger. In India, wearing topaz above the heart was thought to ensure a long life, beauty, and intelligence.
Tanzanite, as a more modern birthstone, has developed associations with transformation, intuition, and spiritual growth. It is considered a stone of connection, facilitating communication with higher realms and promoting self-awareness.
Care and Maintenance
Proper care is essential to maintain the beauty of these December birthstones. Due to its relative softness, turquoise requires gentle handling and should be protected from scratches and harsh chemicals. Cleaning can be done with a soft cloth and mild soapy water. Avoid ultrasonic cleaners and steam cleaners.
Blue Topaz, being more durable, can withstand more rigorous cleaning. However, it is still advisable to avoid harsh chemicals and abrasive materials. Warm, soapy water and a soft brush are sufficient for cleaning.
Tanzanite, while relatively durable, is susceptible to damage from heat and sudden temperature changes. Cleaning should be done with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaners. Professional cleaning is recommended for valuable pieces.
Conclusion
December’s birthstones – Turquoise, Blue Topaz, and Tanzanite – offer a captivating blend of history, beauty, and symbolism. From the ancient origins of turquoise to the modern discovery of tanzanite, each gem holds a unique place in the world of gemstones. Their diverse properties and vibrant colors make them ideal choices for jewelry and meaningful gifts, connecting wearers to a rich tapestry of cultural and geological narratives. When choosing between these gemstones, consider not only their aesthetic appeal but also their individual significance and the care required to maintain their lasting beauty.