December and October each boast a fascinating array of birthstones, offering a spectrum of colors and histories. While December is represented by turquoise, tanzanite, and zircon, October claims opal and tourmaline as its traditional and modern stones. This article will delve into the unique characteristics, historical significance, and gemological properties of these five gemstones, drawing exclusively from available sources.
A History of Significance
Throughout history, gemstones have been valued not only for their beauty but also for the beliefs and symbolism attached to them. Turquoise, a December birthstone, holds a particularly long and rich history. Cherished for millennia, it adorned the pharaohs of ancient Egypt and was carved by Chinese artisans over 3,000 years ago. It was believed to guarantee health and good fortune, and from the 13th century onward, was thought to protect against falls and impending disaster.
October’s opal also carries a history steeped in lore. Associated with light and magic, some cultures credited opals with healing properties, particularly for the eyes, and even the power to grant invisibility. While some superstitions surround the stone, others view it as a symbol of good luck.
Tourmaline, the modern October birthstone, gained prominence more recently, with opals being favored for much of history. The other December birthstones, tanzanite and zircon, have more recent histories of recognition as gemstones, with tanzanite only being discovered in the 20th century.
Geological Formation and Sources
The origins of these gemstones vary considerably. Turquoise is a semi-translucent to opaque gem, often exhibiting veins of matrix – remnants of the rock in which it formed. It is frequently found alongside sapphire deposits, with notable sources including Sri Lanka, Australia, Myanmar, Vietnam, and Cambodia.
Tanzanite, a relatively recent discovery, is often found near sapphire sources as well, reinforcing the geological connection between the two gems.
Zircon, ranging in color from blue to orange and red, is commonly heat-treated to enhance its hues. Opal, unique in its display of “play-of-color,” is formed in a way that creates its dazzling internal flashes. Tourmaline, a complex borosilicate mineral, comes in a wide range of colors and is found in various geological settings. Specific mining locations for tourmaline are not detailed in the provided sources.
Gemological Properties
Each of these gemstones possesses distinct gemological properties. Turquoise, while visually striking, is relatively soft. Tanzanite registers between 6 and 7 on the Mohs scale of hardness, making it susceptible to scratching and abrasion. It can also crack if exposed to sudden temperature changes or very high temperatures and is vulnerable to attack by hydrochloric and hydrofluoric acids. The color of tanzanite is often achieved through heat treatment of brownish zoisite, a process that results in a permanent color change with no additional durability concerns.
Zircon ranges from 6 to 7.5 on the Mohs scale. While generally stable, heat-treated zircon can revert to its original color with prolonged exposure to bright light. It is also prone to abrasion and is best suited for jewelry not subjected to rough wear.
Opal, while visually captivating, is considered the most delicate of commonly worn gemstones, requiring special care. The unique “play-of-color” exhibited by some opals is a phenomenon found in no other gem.
Tourmaline’s properties are not detailed in the provided sources, but it is noted for its diverse color range.
The following table summarizes the hardness of the December birthstones:
| Gemstone | Mohs Hardness |
|---|---|
| Tanzanite | 6-7 |
| Turquoise | Not specified |
| Zircon | 6-7.5 |
Symbolism and Metaphysical Beliefs
Beyond their physical properties, these gemstones have accumulated layers of symbolism over time. Turquoise has long been associated with health, good fortune, and protection. It was believed to safeguard against falls and warn of approaching danger.
Opals, due to their dynamic appearance, have been linked to light and magic, with some believing they possessed healing powers. Despite some negative superstitions, they are also worn for good luck.
Citrine, a November birthstone mentioned in relation to color comparison, is associated with healing and happiness, offering relief from ailments like stomach aches and insomnia. While not a December or October birthstone, its inclusion highlights the historical association of color with healing properties.
The provided sources do not detail specific metaphysical beliefs associated with tanzanite, zircon, or tourmaline.
Care and Cleaning
Proper care is essential to maintain the beauty of these gemstones. Tanzanite is best set in earrings or pendants to minimize wear. Ultrasonic and steam cleaners are not recommended for tanzanite, and warm, soapy water is the preferred cleaning method.
Zircon should be avoided in rough conditions, such as during gardening or sports, to prevent abrasion. Cleaning should be done with a soft brush and mild soap in warm water; ultrasonic and steam cleaners are also not recommended.
The sources do not provide specific care instructions for turquoise, opal, or tourmaline, but given turquoise’s relative softness and opal’s delicate nature, gentle handling and avoiding harsh chemicals are advisable.
December’s Blue Hues and October’s Variety
December offers a choice of three blue-toned birthstones: turquoise, tanzanite, and zircon. This allows for a personalized selection based on preference and budget. Turquoise, being a more traditional and often less expensive option, remains popular. Tanzanite and zircon offer more modern alternatives with unique color variations.
October, in contrast, presents a choice between the dynamic play-of-color of opal and the diverse hues of tourmaline. Opal’s unique optical properties make it a captivating choice, while tourmaline’s range of colors provides versatility.
Conclusion
The birthstones associated with December and October – turquoise, tanzanite, zircon, opal, and tourmaline – represent a rich tapestry of history, geological formation, and gemological properties. From the ancient symbolism of turquoise to the modern appeal of tanzanite and the delicate beauty of opal, each gemstone offers a unique connection to the natural world and a captivating story to tell. The choice of which stone to celebrate is a personal one, reflecting individual preferences and a connection to the enduring allure of these remarkable gems.