For those born on October 19, the assignment of a birthstone is not singular but dual, representing a unique and richly symbolic pair: Opal and Tourmaline. This distinctive pairing, officially recognized for the month of October, offers a fascinating study in contrast and complementarity. While Opal is celebrated for its ethereal play-of-color and long-standing association with hope and transformation, Tourmaline is revered for its remarkable diversity of hues and protective energies. Together, they form a dynamic duo that reflects the balance of nature and human emotion, making them profoundly meaningful for personal adornment, spiritual well-being, and as enduring symbols of the vibrant and transformative qualities of October.
This comprehensive guide delves into the history, geological makeup, and cultural significance of these two gemstones, offering an in-depth exploration of their properties, symbolism, and care. Whether you are a gemstone enthusiast, a jewelry buyer, or a student of gemology, this analysis will provide a deeper understanding of the October 19 birthstone, illuminating the unique characteristics that define each stone and the shared legacy they hold.
History and Lore
The use of Opal and Tourmaline as gemstones dates back centuries, with each stone carrying its own set of legends and meanings across various cultures.
Opal: The Stone of Hope and Transformation
Opal has long been associated with hope, purity, and transformation. Its name is believed to have originated in India, the source of the first opals brought to the Western world, where in Sanskrit it was called upala, meaning “precious stone.” In ancient Rome, this became opalus. The gem’s dramatic play-of-color—its most defining characteristic—has inspired writers to compare it to fireworks, galaxies, and volcanoes. Bedouins once believed opal held lightning and fell from the sky during thunderstorms. Ancient Greeks thought opals bestowed the gift of prophecy and protection from disease. For centuries, Europeans maintained opal as a symbol of purity, hope, and truth. Opal was even believed to embody the virtues and powers of all colored stones. Beyond its lore, opal is also the traditional stone given to celebrate the 14th wedding anniversary.
Tourmaline: The Stone of Artistic Expression and Protection
Tourmaline is the newer October birthstone, its name deriving from the Sinhalese word toramalli, meaning “mixed colored stones,” or turmali, reflecting its incredible color diversity. This name was given by Sri Lankan gem traders who encountered crystals with multiple colors in a single stone. Because of its vast range of colors, tourmaline was often mistaken for other gemstones throughout history. One of the “rubies” in the Russian crown jewels, the “Caesar’s Ruby” pendant, is actually red (rubellite) tourmaline. A Spanish conquistador found green tourmaline crystals in Brazil in the 1500s and confused the stones with emerald. Ancient mystics believed this October birthstone could inspire artistic expression, as it possesses a color palette for every mood. Among the most popular varieties are the pink and red rubellites, the emerald green “chrome” tourmalines, and the neon green and blue-to-violet “paraíba” tourmalines.
Geological Formation and Sources
The geological origins and mining locations of Opal and Tourmaline are as distinct as their appearances.
Opal Formation and Sources
Opal is not a crystalline mineral but a form of amorphous silica. It is formed from a solution of silicon dioxide and water that seeps into rock crevices. As the water evaporates, it leaves behind deposits of silica, which form a solid gel. The unique play-of-color in precious opal is caused by a microscopic grid of silica spheres that diffract light.
The opal birthstone can be found in many places worldwide. The fields of Australia are the most productive in the world for opal. Major Australian opal fields include Coober Pedy, Lightning Ridge, and Andamooka. Other important sources include Ethiopia, Mexico, and Brazil. Ethiopian opal, particularly from the Wollo region, has gained significant prominence in the market for its vibrant play-of-color, though it can be more sensitive to water. Mexican opal is often found in volcanic rock and can display a cat’s eye effect. Brazilian opal is known for its bright colors and is often more stable.
Tourmaline Formation and Sources
Tourmaline is a complex cyclosilicate mineral that forms in a variety of geological environments, most commonly in pegmatites—coarse-grained igneous rocks that form from the cooling of magma. It can also be found in metamorphic rocks. Its chemical complexity allows for a wide range of colors, as trace elements like iron, manganese, and chromium replace elements in its crystal structure.
Tourmaline is mined globally, with significant deposits found in Brazil, which is a leading source for many varieties, including the coveted paraíba tourmaline (though the finest paraíba comes from a specific mine in Brazil). Afghanistan is a major source for high-quality rubellite (red tourmaline) and indicolite (blue tourmaline). Other important sources include Madagascar, Nigeria, and the United States (particularly Maine and California, which have historical significance for tourmaline mining). The diversity of sources contributes to the stone’s wide range of colors and price points.
Gemological Properties
The physical and optical properties of Opal and Tourmaline differ significantly, which influences their durability, care, and use in jewelry.
Opal
Opal is prized for its unique optical phenomenon, play-of-color, rather than for its hardness. It is a relatively soft gemstone, ranking between 5 and 6.5 on the Mohs scale of hardness. This makes it susceptible to scratching and abrasion. Opal has no cleavage, meaning it does not have a natural tendency to break along specific planes, but it has a conchoidal fracture and can be brittle, making it prone to chipping or cracking if struck hard or exposed to sudden temperature changes. Its refractive index is typically low, around 1.37 to 1.45, and it lacks strong birefringence. Opal’s specific gravity ranges from 1.98 to 2.20. It is typically cut into cabochons to best display its play-of-color, though it can also be carved or used in beads.
Tourmaline
Tourmaline is a much harder and more durable gemstone, ranking 7 to 7.5 on the Mohs scale, making it suitable for everyday wear in jewelry. It has a trigonal crystal system and exhibits strong pleochroism, meaning it can show different colors when viewed from different crystal directions. Its refractive index ranges from approximately 1.62 to 1.65, and it has a specific gravity between 3.00 and 3.26. Tourmaline has a vitreous luster and can be cut into a wide variety of shapes and facets, from traditional brilliant cuts to smooth cabochons that may display phenomena like cat’s eyes or asterism. Its durability and color stability make it a versatile choice for all types of jewelry.
The following table summarizes key gemological properties based on the provided sources:
| Property | Opal | Tourmaline |
|---|---|---|
| Mohs Hardness | 5 - 6.5 | 7 - 7.5 |
| Crystal System | Amorphous (non-crystalline) | Trigonal |
| Refractive Index | ~1.37 - 1.45 | ~1.62 - 1.65 |
| Specific Gravity | 1.98 - 2.20 | 3.00 - 3.26 |
| Key Phenomenon | Play-of-color (diffraction) | Pleochroism, occasional cat's eye |
| Typical Cut | Cabochon | Faceted, cabochon, carved |
Symbolism and Metaphysical Beliefs
The symbolic meanings attributed to Opal and Tourmaline are deeply rooted in history and continue to influence their appeal today.
Symbolism of Opal
Opal has been historically linked to hope, purity, and truth. Its shifting colors are seen as a metaphor for change and transformation, making it a stone of emotional balance and creativity. In modern metaphysical beliefs, opal is often associated with enhancing imagination, inspiring creativity, and facilitating emotional healing. It is considered a stone of inspiration, encouraging spontaneity and freeing one from rigid thought patterns. For those born on October 19, opal symbolizes the capacity for personal growth and the hopeful embrace of life’s changes.
Symbolism of Tourmaline
Given its vast color spectrum, tourmaline’s symbolism is often color-specific, though it is generally regarded as a stone of protection and grounding. Black tourmaline is known for its ability to repel negative energy, while pink tourmaline is associated with love and compassion. Green tourmaline is linked to vitality and success, and blue tourmaline is believed to promote communication and calm. As a whole, tourmaline is thought to inspire artistic expression, provide emotional stability, and balance the mind and body. Its protective reputation makes it a popular talisman for travelers and those seeking to ward off harm. For the October 19 birthstone bearer, tourmaline represents creativity, grounding, and the full spectrum of emotional expression.
Care and Cleaning
The differing physical properties of Opal and Tourmaline necessitate distinct care instructions to preserve their beauty and integrity.
Caring for Opal
Due to its low hardness and potential for cracking, opal requires careful handling. It should be stored separately from other jewelry to prevent scratches. Opals are sensitive to chemicals, so avoid exposing them to household cleaners, cosmetics, and perfumes. Cleaning should be done gently with warm, soapy water and a soft brush. It is crucial to avoid ultrasonic cleaners, steam cleaners, and sudden temperature changes, as these can cause internal fractures or dehydration, especially in porous varieties like Ethiopian opal. Prolonged exposure to dry conditions or intense heat can lead to crazing (fine cracks). For jewelry with opal settings, professional cleaning by a jeweler familiar with opals is recommended.
Caring for Tourmaline
Tourmaline is more robust and easier to care for. Its hardness of 7-7.5 makes it resistant to everyday wear and scratching. It can be cleaned with warm, soapy water and a soft brush. Ultrasonic cleaners are generally safe for most tourmaline, but it is advisable to avoid them for stones with visible inclusions or fractures. Steam cleaning is also typically safe, but caution should be exercised with stones that have been treated with heat or fracture-filled. Tourmaline is stable under normal light and heat, but as with all gemstones, it is best to avoid sudden extreme temperature changes. Its durability makes it an excellent choice for rings, bracelets, and pendants intended for daily wear.
Conclusion
October 19 is a unique date in the world of birthstones, as it is associated with two distinct yet complementary gemstones: Opal and Tourmaline. Opal, with its play-of-color and ethereal glow, symbolizes hope, transformation, and emotional balance, while Tourmaline, with its vibrant hues and protective energies, represents creativity, grounding, and emotional stability. These two gemstones offer a fascinating contrast in their geological formation, physical properties, and cultural significance, yet they share a common role in celebrating the beauty of change and the power of color. Whether used in jewelry, spiritual practices, or personal adornment, Opal and Tourmaline are enduring symbols of resilience, creativity, and emotional healing. For those born on October 19, or for those who are drawn to the enchanting allure of Opal and the versatile charm of Tourmaline, these gemstones offer a rich and meaningful connection to the natural world and the human spirit.