October boasts two recognized birthstones: tourmaline and opal. While tourmaline gained prominence as a modern addition, opal holds the distinction as the traditional October birthstone, steeped in history and celebrated for its captivating “play-of-color.” This article delves into the fascinating world of opal, exploring its origins, geological properties, historical significance, and the enduring beliefs surrounding this unique gemstone.
History and Lore
The story of opal begins in ancient times, with its name believed to originate from the Sanskrit word upala, meaning “precious stone.” This term evolved into opalus in ancient Rome. Throughout history, opal has been revered and imbued with diverse meanings. Ancient Greeks associated the stone with the gift of prophecy and protection from disease. Indian mythology tells of the Virgin Goddess of the Rainbow transforming into an opal by the Mother Goddess, pursued by Brahma, Vishnu, and Shiva. Europeans long considered opal a symbol of purity, hope, and truth, believing it embodied the virtues of all colored stones.
Despite its long-held positive associations, opal experienced a period of undeserved misfortune. A relatively recent reputation for being unlucky arose due to its delicate nature – opal is a softer stone prone to breakage. This led to a misconception that it was unsuitable for all but those born in October. However, for centuries prior, opal was widely regarded as a stone of luck and magic.
Beyond its symbolic meanings, opal has also played a role in significant historical events. In the late 1800s, the Empress Dowager Tzu-Hsi of China developed a fervent passion for pink tourmaline, acquiring nearly the entire production from California mines. Even in death, her devotion continued, as she was buried with a pink tourmaline pillow, and the remainder of her collection was crafted into exquisite carvings. Opal is also traditionally given to celebrate the 14th wedding anniversary.
Geological Formation and Sources
Opal is unique among gemstones as it is not a crystalline mineral but rather a mineraloid. It is formed by the gradual natural heating of silica gel found in the cracks and voids of rocks. This silica gel, combined with water content, hardens over time to create the opal’s characteristic structure. The presence of microscopic silica spheres is crucial to opal’s defining feature: its play-of-color.
While opal has been sourced from various locations throughout history, Australia is currently the world’s primary producer. The first opals brought to the Western world originated in India. However, the discovery of rich mines in Australia significantly increased the availability of this prized gemstone.
Gemological Properties
Opal’s defining characteristic is its “play-of-color,” a mesmerizing display of shifting rainbow hues. This phenomenon occurs as light enters the stone and is diffracted by the microscopic silica spheres within. The size and arrangement of these spheres determine the colors observed.
Here’s a summary of opal’s key gemological properties:
| Property | Value |
|---|---|
| Hardness (Mohs) | 5.5 - 6.5 |
| Specific Gravity | 1.98 - 2.20 |
| Refractive Index | 1.450 |
| Composition | Hydrated Silica |
| Transparency | Translucent to Opaque |
Opal exists in two primary varieties: precious and common. Precious opal exhibits the play-of-color effect, while common opal does not. The presence of water content is essential for opal’s structure and play-of-color; dehydration can lead to cracking and loss of vibrancy.
Symbolism and Metaphysical Beliefs
Throughout history, opal has been attributed with various metaphysical properties. It is believed to correspond to the sacral chakra, and imbalances in this energy center are thought to contribute to addictive behaviors. Opal is said to moderate and harmonize sexual desire, promoting emotional balance.
The “fire” within an opal is often associated with sparking creativity and inspiring a joyful outlook on life. It is considered a stone of hope, purity, and truth, encouraging confidence and optimism in the wearer. Some believe opal can bestow the gift of prophecy, echoing the ancient Greek belief in its divinatory powers.
Care and Cleaning
Due to its relatively soft nature (5.5-6.5 on the Mohs scale), opal requires careful handling and cleaning. It is susceptible to scratches and can be damaged by harsh chemicals or extreme temperatures. To clean opal jewelry, it is best to use a soft cloth and lukewarm soapy water. Avoid ultrasonic cleaners and harsh abrasives. Storing opal jewelry separately from harder gemstones will help prevent scratches. Maintaining a moderate level of humidity can also help prevent cracking, as dehydration can damage the stone.
Conclusion
Opal, the traditional October birthstone, is a gemstone of remarkable beauty and rich history. From its ancient origins in India to its modern-day prominence as a symbol of hope and creativity, opal continues to captivate and inspire. Its unique play-of-color, coupled with its intriguing lore, makes it a truly special and cherished gemstone. While concerns about its durability have led to the addition of tourmaline as a second October birthstone, opal remains a timeless classic, embodying the vibrant and diverse spirit of those born in the tenth month.