October boasts not one, but two recognized birthstones: opal and tourmaline. Both gems offer a dazzling spectrum of colors and a rich history, making them captivating choices for those born in the tenth month. While opal holds the traditional designation, tourmaline gained recognition as a modern alternative in 1912, expanding the options for October birthdays. This article will delve into the history, geological origins, gemological properties, symbolism, and care of these two remarkable gemstones.
History and Lore
Opal’s history is steeped in ancient beliefs and captivating tales. Its name is believed to originate from the Sanskrit word upala, meaning “precious stone,” and later adopted as opalus by the Romans. Throughout history, opal has inspired diverse interpretations. Ancient Greeks associated the gem with the gift of 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. It is also the traditional stone gifted to celebrate a 14th wedding anniversary.
Tourmaline’s name derives from the Sinhalese word toramalli, meaning “stone with mixed colors,” a fitting description given the gem’s propensity for displaying multiple hues within a single crystal. Ancient mystics believed tourmaline could inspire artistic expression, likely due to its diverse color palette.
Geological Formation and Sources
Opal formation is a unique geological process. It is typically found in sedimentary rock, forming from silica-rich solutions that seep into cracks and voids. As the water evaporates, it leaves behind deposits of silica spheres, which create the characteristic play-of-color. The most productive opal fields are located in Australia, particularly in Lightning Ridge, New South Wales, famed for its prized black opal. White opal is found in areas like White Cliffs, Mintabie, and Coober Pedy in South Australia, while Boulder opal is exclusively mined in Queensland. Significant opal deposits are also found in Ethiopia, Mexico, and Brazil, with smaller occurrences in Central Europe, Honduras, Indonesia, Madagascar, Peru, Turkey, and the United States.
Tourmaline forms in igneous and metamorphic rocks, often in pegmatites, which are coarse-grained igneous rocks. The gem’s diverse colors are attributed to trace elements present during its formation. While specific locations for tourmaline mining are not detailed in the provided sources, the gem is known to exhibit a wide range of colors, including pink and red rubellites, emerald green “chrome” tourmalines, and neon green and blue-to-violet “paraíba” tourmalines.
Gemological Properties
Opal’s hardness ranges from 5 to 6.5 on the Mohs scale, making it relatively softer than many other gemstones. This lower hardness means opal is susceptible to scratches from harder gems like diamonds, rubies, sapphires, and emeralds, and should be stored separately to prevent damage. Prolonged exposure to water can also weaken the adhesive in opal doublets and triplets, which are constructed layers of opal and backing material. Furthermore, opal can fracture if exposed to high heat or sudden temperature changes. Opal is often treated by impregnation with oil, wax, or plastic to enhance its appearance and stability. Opal doublets and triplets consist of fine slices of opal glued to a base material and covered with a clear quartz dome.
Tourmaline’s name reflects its often multi-colored nature. The sources do not provide a specific Mohs hardness for tourmaline, but it is generally known to be a durable gemstone. The gem’s color palette is exceptionally diverse, with popular varieties including pink and red rubellites, emerald green “chrome” tourmalines, and the highly sought-after neon green and blue-to-violet “paraíba” tourmalines.
Symbolism and Metaphysical Beliefs
Opal has long been associated with hope, purity, and truth. Its dramatic play-of-color has inspired comparisons to fireworks, galaxies, and volcanoes, reflecting its vibrant and dynamic nature.
Tourmaline is believed to inspire artistic expression, potentially due to its wide range of colors. Pink tourmaline, in particular, is associated with friendship, compassion, and balance. It is considered a heart-centered stone.
Alternative birthstones are also linked to astrological signs and guardian angels. According to one system, garnet is associated with Aquarius, amethyst with Pisces, bloodstone with Aries, sapphire with Taurus, agate with Gemini, emerald with Cancer, onyx with Leo, carnelian with Virgo, chrysolite with Libra, beryl with Scorpio, topaz with Sagittarius, and ruby with Capricorn. Guardian angels are also linked to specific birthstones, with onyx associated with Gabriel in January, jasper with Barchiel in February, and ruby with Malchediel in March. The term “chrysolite” historically encompassed yellow-green chrysoberyl, peridot, and prehnite, but these are now recognized as distinct gem species.
Care and Cleaning
The safest way to clean opal is with warm, soapy water. More abrasive cleaning methods may damage the opal or any filler material present in doublets or triplets. It’s important to avoid prolonged exposure to water, especially for opal doublets and triplets, as this can weaken the adhesive. Opal should be stored separately from harder gemstones to prevent scratching.
Specific cleaning instructions for tourmaline are not provided in the sources, but its relative durability suggests it can withstand gentle cleaning with warm, soapy water.
Conclusion
October’s birthstones, opal and tourmaline, represent a captivating blend of history, beauty, and symbolism. Opal, with its ancient lore and mesmerizing play-of-color, remains a traditional favorite. Tourmaline, recognized as a modern alternative, offers a dazzling array of colors and a connection to artistic inspiration. Both gemstones provide a radiant and meaningful way to commemorate birthdays in the tenth month.