October boasts not one, but two recognized birthstones: the captivating opal and the vibrant pink tourmaline. Both gemstones offer a stunning array of colors and possess unique histories, 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 diverse spectrum of pink hues and remarkable durability. This article will delve into the history, geological origins, gemological properties, symbolism, and care of both opal and pink tourmaline, providing a comprehensive overview of these fascinating gemstones.
A History Intertwined with Lore
The story of opal stretches back to ancient times. Its name is believed to originate from the Sanskrit word upala, meaning “precious stone,” which evolved into opalus in ancient Rome. Throughout history, opal has inspired a wealth of beliefs and legends. Ancient Greeks associated the stone with prophecy and protection from disease, while Bedouins believed opals contained lightning and descended from the sky during thunderstorms. Europeans once considered opal a symbol of purity, hope, and truth, believing it embodied the virtues of all colored stones. These dramatic displays of color were often likened to fireworks, galaxies, and volcanoes.
Pink tourmaline, while appreciated for centuries, gained significant recognition in the late 19th century. The Empress Dowager Tzu-Hsi of China developed a particular fondness for the gem, acquiring nearly the entire production from California mines. Her passion continued even after her death, as she was buried with a pink tourmaline pillow, and the remainder of her collection was crafted into exquisite carvings. The name "tourmaline" itself comes from the Sinhalese word turamali, meaning “stone of mixed color,” a fitting description given the gem’s diverse color range.
Geological Formation and Sources
Opals are formed from silica-rich water that seeps into cracks and voids in the earth. Over millions of years, this water deposits microscopic silica spheres, which arrange themselves into a regular pattern, creating the play-of-color that defines many opals. Australia is the world’s primary source of opal, accounting for over 95% of global production. Within Australia, Lightning Ridge is renowned for its black opals, characterized by a dark background that intensifies the play-of-color. Other Australian sources include Coober Pedy and White Cliffs, known for white opal, and Queensland, where boulder opal – a unique combination of opal and ironstone – is found. Mexico, particularly the state of Querétaro, is also a significant source of fire opal, known for its vibrant red, orange, and yellow hues.
Pink tourmaline forms in distinctive prism-like crystals with long hexagonal structures. High-quality specimens originate from several locations worldwide, including Brazil, Nigeria, Mozambique, and various regions of West Africa. The gem contains a diverse variety of elements, with most jewelry-quality tourmalines consisting primarily of the mineral elbaite. Some tourmaline crystals even exhibit multiple colors, known as watermelon tourmaline. Varieties with more raspberry or purple tones are classified as rubellite.
Gemological Properties: A Comparative Look
Both opal and pink tourmaline possess distinct gemological properties that contribute to their unique appeal.
Opal: Opal is unique in that it is an amorphous mineral, lacking a defined crystalline structure. Its play-of-color, the shifting rainbow hues, is its most defining characteristic. However, not all opals exhibit this phenomenon. Different varieties of opal are categorized based on their background color and the presence or absence of play-of-color. These include:
- Black Opal: Dark background, broad rainbow patterns.
- Crystal Opal: Transparent with superior play-of-color.
- Water Opal: Colorless or light base color, subtle play-of-color.
- Boulder Opal: Opal combined with host rock (matrix).
- Fire Opal: Red, orange, or yellow background, often lacking play-of-color.
Opal is relatively soft, measuring between 5.5 and 6.5 on the Mohs hardness scale.
Pink Tourmaline: Pink tourmaline measures 7-7.5 on the Mohs hardness scale, making it more durable than opal and suitable for everyday wear. It forms in long, hexagonal prism-like crystals. The color variations within pink tourmaline are extensive, ranging from delicate blush pinks to vibrant magenta hues.
The following table summarizes key gemological properties:
| Property | Opal | Pink Tourmaline |
|---|---|---|
| Chemical Formula | SiO₂·nH₂O | Complex Borosilicate |
| Hardness (Mohs) | 5.5 - 6.5 | 7 - 7.5 |
| Crystal System | Amorphous | Trigonal |
| Play-of-Color | Often Present | Absent |
| Transparency | Transparent-Opaque | Transparent-Opaque |
Symbolism and Metaphysical Beliefs
Throughout history, both opal and pink tourmaline have been imbued with symbolic meaning. As previously mentioned, opal has been associated with hope, purity, truth, and prophecy. However, it has also been considered by some to be unlucky, a belief stemming from a historical association with misfortune following a publication of a novel featuring an opal-wearing character. This duality contributes to opal’s intriguing mystique.
Pink tourmaline is often associated with love, compassion, and emotional healing. It is believed to promote emotional balance and encourage self-love. The gem is also thought to inspire creativity and artistic expression.
Care and Cleaning
Due to its relative softness, opal requires careful handling. It is susceptible to scratches and can be damaged by sudden temperature changes. Avoid exposing opal to harsh chemicals or ultrasonic cleaners. Cleaning opal jewelry can be done with a soft cloth and mild soapy water.
Pink tourmaline, being more durable, is easier to care for. Simple soap and water are sufficient to maintain its shine. However, excessive heat should be avoided, as it can damage the gem. Avoid using harsh chemicals when cleaning pink tourmaline jewelry.
Conclusion
Opal and pink tourmaline represent the captivating beauty and diverse geological origins of October’s birthstones. Opal, with its mesmerizing play-of-color and rich history, continues to enchant jewelry lovers and collectors. Pink tourmaline, with its vibrant hues and impressive durability, offers a modern and enduring alternative. Both gemstones hold unique symbolic meanings and require specific care to maintain their brilliance, making them treasured possessions for those born under the October sky.