October is uniquely blessed with not one, but two recognized birthstones: opal and pink tourmaline. Both gemstones offer a stunning array of colors and possess a rich history, making them cherished choices for those born in the tenth month. While opal holds the distinction as the traditional October birthstone, pink tourmaline has gained prominence as the modern alternative, offering a vibrant spectrum of hues and captivating beauty. This article will delve into the history, geological origins, gemological properties, and symbolism of both opal and pink tourmaline, providing a comprehensive overview of these fascinating gemstones.
A History of Shifting Colors and Imperial Favor
The story of opal stretches back millennia. Its name is believed to originate from the Sanskrit word upala, meaning “precious stone,” which evolved into opalus in ancient Rome. Ancient Greeks associated opal with the gift of prophecy and protection from disease, while Bedouins believed the stone contained lightning and descended from the sky during thunderstorms. Throughout history, opal has been revered for its dramatic “play-of-color,” a phenomenon likened to fireworks, galaxies, and volcanoes. For centuries, it was considered a symbol of purity, hope, and truth, embodying the virtues of all colored stones. Opal is also traditionally given to celebrate the 14th wedding anniversary.
Pink tourmaline, while also possessing a long history, gained significant recognition more recently. In the late 19th century, the Empress Dowager Tzu-Hsi of China developed a fervent passion for pink tourmaline, acquiring nearly the entire production from California mines. Her devotion continued after her death, as she was buried with a pillow crafted from the gemstone, and the remainder of her collection was transformed into intricate carvings. This imperial patronage significantly elevated the status of pink tourmaline.
The dual designation of birthstones for October is a relatively modern development. Until 1912, opal was the sole birthstone for the month. However, the National Association of Jewelers revised the list, allowing for alternate gems for months whose traditional stones were either rare or not widely understood. Tourmaline, with its diverse color palette, was chosen as a co-birthstone, offering October-born individuals a wider range of choices.
Geological Formation and Global Sources
Opal is unique among gemstones as it is not a crystalline mineral but rather a mineraloid – an amorphous silica gel. It forms through the gradual natural heating of silica gel found within cracks and voids in rocks. The play-of-color, opal’s most defining characteristic, is a result of the diffraction of light by microscopic spheres of silica within its structure.
The vast majority of the world’s precious opal originates from Australia, accounting for approximately 95% of global production. However, opal is also found in Brazil, Mexico, Honduras, and the western United States.
Pink tourmaline, conversely, is a crystalline mineral belonging to the tourmaline group. It forms in distinctive prism-like crystals with long hexagonal structures. The color pink in tourmaline is attributed to the presence of manganese and iron. Major mining locations for tourmaline include Brazil, Tanzania, Nigeria, Kenya, Madagascar, Mozambique, Malawi, and Namibia. The most prized and rare variety, Paraíba tourmaline, a copper-bearing gem, is found in Brazil and exhibits intense shades of violet-blue and blue-green.
Gemological Properties: A Comparative Overview
While both opal and pink tourmaline are beautiful gemstones, their gemological properties differ significantly.
| Property | Opal | Pink Tourmaline |
|---|---|---|
| Chemical Formula | Hydrated amorphous silica (SiO₂·nH₂O) | Complex borosilicate (variable) |
| Hardness (Mohs) | 5.5 – 6.5 | 7 – 7.5 |
| Specific Gravity | 1.98 – 2.15 | 3.05 – 3.49 |
| Crystal System | Amorphous | Trigonal |
| Color | Variable; displays play-of-color | Pink, red, violet, green, multi-colored |
| Transparency | Translucent to opaque | Transparent to translucent |
| Luster | Vitreous to resinous | Vitreous |
Opal’s defining characteristic is its play-of-color, a visual phenomenon caused by the diffraction of light. This effect is not present in pink tourmaline. Pink tourmaline, on the other hand, exhibits a wider range of pink hues, from delicate blush tones to vibrant magenta shades. Some tourmaline crystals even display multiple colors, known as watermelon tourmaline, featuring pink and green zones.
Symbolism and Metaphysical Beliefs
Throughout history, both opal and pink tourmaline have been attributed with various symbolic meanings and metaphysical properties. Opal is often associated with hope, purity, and truth. It is believed to inspire confidence and optimism in the wearer.
Pink tourmaline is thought to promote feelings of self-love, emotional balance, and release of emotional blockages. Some believe it increases understanding and empathy, while also warding off negative energy. Tourmaline is even piezoelectric, meaning it can generate an electrical charge when pressure is applied, and has been used in practical applications like pressure gauges.
Care and Cleaning
Due to their differing hardness levels, opal and pink tourmaline require different care routines. Opal, with a Mohs hardness of 5.5-6.5, is relatively soft and susceptible to scratches and chipping. It should be stored separately from harder gemstones and cleaned with a soft cloth and mild soapy water. Avoid ultrasonic cleaners and harsh chemicals.
Pink tourmaline, with a hardness of 7-7.5, is more durable and can withstand more wear and tear. It can be cleaned with warm soapy water and a soft brush. Ultrasonic cleaners are generally safe for pink tourmaline, but caution should be exercised with stones that may have inclusions.
Conclusion
Opal and pink tourmaline represent the captivating duality of October’s birthstones. Opal, with its ethereal play-of-color and ancient lore, embodies hope and inspiration. Pink tourmaline, with its vibrant hues and modern appeal, symbolizes love, emotional healing, and empathy. Whether one chooses the traditional opal or the modern pink tourmaline, both gemstones offer a beautiful and meaningful connection to the tenth month of the year. Their unique geological origins, distinct gemological properties, and rich cultural significance make them treasured possessions for generations to come.