December is unique among the months, boasting not one, but four recognized birthstones: blue zircon, turquoise, tanzanite, and blue topaz. All share a common thread – a captivating blue hue – yet each possesses distinct geological origins, historical significance, and attributed meanings. This article will delve into the characteristics of each of these December birthstones, exploring their history, gemological properties, and cultural relevance, as understood through available sources.
History and Lore
The history of December’s birthstones is rich and varied. Turquoise, perhaps the oldest of the group, has been cherished for millennia. Ancient Egyptians, pharaohs and rulers alike, adorned themselves with turquoise, and Chinese artisans were carving the stone over 3,000 years ago. Belief in its protective powers was widespread; from the 13th century onward, it was thought to safeguard against falls, particularly from horses, and to warn of impending disaster by fracturing. In Hindu traditions, viewing turquoise after a new moon was believed to bring great wealth.
Zircon, while sometimes confused with cubic zirconia, has a long history as a diamond substitute due to its brilliance and high refractive index. Its use dates back centuries, though its lore is less consistently documented than that of turquoise. Historically, zircon was believed to bring good sleep and protection. Greek mythology connects the stone, specifically the red variety known as hyacinth, to themes of rebirth.
Tanzanite is the newest addition to the December birthstone family, discovered relatively recently in Tanzania. As such, its historical lore is still developing, but it has quickly gained recognition for its beauty and rarity.
Blue topaz, a popular and affordable alternative, has also been used in jewelry for a considerable period, though its historical significance is less pronounced than that of turquoise or zircon.
Geological Formation and Sources
The origins of these gemstones are geographically diverse. Blue zircon is mined primarily in Thailand, Cambodia, and Vietnam. Interestingly, zircon contains trace amounts of uranium and thorium, making it valuable in radiometric dating, with some specimens calculated to be up to 4.4 billion years old – among the oldest minerals on Earth. While large zircon specimens are occasionally found, most gems on the market are relatively small.
Turquoise forms in relatively dry, arid environments, often in association with copper deposits. Its characteristic matrix, the remnants of the surrounding rock, is a defining feature.
Tanzanite is found in a very limited geographical area: the Merelani Hills of northern Tanzania. This singular source contributes to its rarity and value.
Blue topaz is often created through the heat treatment of naturally occurring colorless topaz. While natural blue topaz exists, it is much rarer.
Gemological Properties
Each of these gemstones possesses unique gemological properties. Turquoise is a semi-translucent to opaque gem, ranging in color from blue to green. Its quality is graded on color, matrix, and texture, with dense textures exhibiting better polish luster. The most valuable turquoise displays a bright “robin’s egg” or “sky” blue color with even distribution.
Zircon exhibits a wider range of colors, but blue zircon is the most popular. It is often greenish in tone and almost always heat-treated to achieve its blue hue. Zircon’s color can be affected by radioactive elements, leading to changes in its crystalline structure over time. “High zircon” specimens, typically blue or colorless, are preferred for jewelry. Zircon’s hardness is 6.5-7.5 on the Mohs scale.
Tanzanite displays a captivating range of purple to blue hues. The most valuable colors are vibrant pure blue, but bright purplish-blue and violet-blue are also highly sought after. Tanzanite is known for its strong pleochroism, meaning it displays different colors when viewed from different angles.
Blue topaz, with a Mohs hardness of 8, is a durable gemstone. It is often available in large sizes and affordable prices, making it a popular alternative to other December birthstones.
The following table summarizes key gemological properties:
| Gemstone | Color(s) | Hardness (Mohs) | Transparency | Notable Features |
|---|---|---|---|---|
| Turquoise | Blue to Green | 5-6 | Opaque | Often contains matrix; graded on texture |
| Blue Zircon | Blue (often greenish) | 6.5-7.5 | Transparent | High refractive index; can be heat-treated |
| Tanzanite | Purple to Blue | 6-7 | Transparent | Strong pleochroism; limited source |
| Blue Topaz | Blue | 8 | Transparent | Durable; often heat-treated from colorless topaz |
Symbolism and Metaphysical Beliefs
Beyond their aesthetic appeal, these gemstones are imbued with symbolic meaning. Turquoise has long been associated with protection, good fortune, and spirituality. Tibetan Buddhists use turquoise in malas for meditation, believing it represents spirituality and luck. Crystal healers recommend it for treating inflammation and deflecting negativity.
Zircon symbolizes success, wisdom, and positivity. The Greek myth of Hyacinth links the stone to rebirth, while white zircon is seen as a symbol of purity and yellow zircon as a “Stone of Prosperity.”
Tanzanite is often referred to as the “Stone of Transformation” and “Stone of Magic,” believed to facilitate communication and spiritual awareness. It is thought to help in resolving relationship disputes and boosting intuition.
While specific metaphysical beliefs surrounding blue topaz are less detailed in the provided sources, the color blue itself is often associated with tranquility, peace, and communication.
Care and Cleaning
The care required for each gemstone varies based on its hardness and other properties. Turquoise, being relatively soft, requires gentle handling and should be protected from scratches and harsh chemicals. Cleaning can be done with a soft cloth and mild soapy water.
Zircon, with its good hardness, is more durable but can still be chipped with a sharp blow. It can be cleaned with warm, soapy water and a soft brush.
Tanzanite is also relatively durable but can be damaged by sudden temperature changes. It should be cleaned with warm, soapy water and a soft brush.
Blue topaz, being quite hard, is relatively resistant to scratches and can be cleaned with warm, soapy water and a soft brush. Ultrasonic cleaners are generally safe for topaz.
Zodiac Birthstones
The provided sources also briefly touch upon the concept of zodiac birthstones, noting that originally, zodiac stones and birthstones were one and the same. However, today, zodiac birthstones are often semi-precious, while standard birthstones can include precious gems. A chart is provided listing birthstones by zodiac sign, though a detailed exploration of this topic is beyond the scope of this article.
Conclusion
December’s birthstones – blue zircon, turquoise, tanzanite, and blue topaz – offer a diverse range of colors, histories, and symbolic meanings. From the ancient protective powers attributed to turquoise to the modern allure of tanzanite, each gemstone holds a unique place in the world of gemology and cultural lore. Whether chosen for their aesthetic beauty, their perceived metaphysical properties, or their connection to a specific date of birth, these December birthstones continue to captivate and inspire.