October boasts a diverse selection of birthstones, offering individuals born in this month a range of beautiful gemstones to choose from. While opal and tourmaline are the most widely recognized October birthstones, jasper and coral also hold significance in certain cultural traditions. This article will delve into the history, geological origins, gemological properties, and symbolism of these stones, drawing upon historical accounts and modern understanding.
A History of October Birthstones
The assignment of specific gemstones to each month has evolved over time. Originally, birthstones were linked to the zodiac signs rather than calendar months. The practice of associating gems with specific months gained traction with the publication of the “Gregorian Birthstone Poems” by Tiffany & Co. in 1870. This pamphlet initially designated opal as the sole October birthstone. However, the National Association of Jewellers (now Jewellers of America) formalized a standardized list in 1912, recognizing opal as the primary October birthstone and tourmaline as an alternative.
Ancient civilizations also attributed significance to these stones. Opal, with its captivating play of color, was revered in ancient Greece as a gift of protection and prophecy. Ancient Romans referred to it as opalu, derived from the Sanskrit word upala, meaning “precious stone.” Bedouins believed opals held fragments of lightning, fallen from the sky during thunderstorms. In the Ayurvedic calendar, opal was also considered the traditional October gemstone.
Coral, particularly the pink-red variety of Corallium rubrum, is the October birthstone in the Hindu calendar. Jasper, a speckled stone, holds this distinction in the old Tibetan calendar.
Geological Formation and Sources
Opal is a unique gemstone, distinct from crystalline structures like diamonds or rubies. It is a hydrated amorphous form of silica, containing water within its structure, and typically forms in fissures of rock, commonly found alongside sandstone, rhyolite, limonite, or basalt. The “play of color” exhibited by opals is a result of the diffraction of light as it passes through microscopic silica spheres within the stone.
Tourmaline, on the other hand, is a crystalline borosilicate mineral. It comes in a wide array of colors, each with its own unique appeal. Pink tourmaline, a popular choice for October, is formed through similar geological processes as other tourmaline varieties.
Coral is an organic gemstone, formed by the skeletal remains of marine invertebrates. Precious coral, the variety most often used in jewelry, is closely linked to reef-building stony coral. The most common variety is Corallium rubrum, known for its warm pink-red hues.
Jasper is a variety of chalcedony, a microcrystalline form of quartz. Its diverse colors and patterns are due to the presence of various minerals and impurities.
Gemological Properties
The gemological properties of these October birthstones vary significantly.
Opal: Opal’s hardness ranges from 5.5 to 6.5 on the Mohs scale, making it relatively soft and susceptible to scratches. Its specific gravity typically falls between 1.98 and 2.50. The defining characteristic of opal is its “play of color,” a phenomenon caused by the diffraction of light.
Tourmaline: Tourmaline’s hardness is considerably higher, ranging from 7 to 7.5 on the Mohs scale, making it more durable than opal. Its specific gravity varies depending on the composition, generally between 3.02 and 3.22. Tourmaline exhibits strong pleochroism, meaning it displays different colors when viewed from different angles.
Coral: Coral is relatively soft, with a Mohs hardness of 3-4. Its specific gravity ranges from 1.26 to 1.34. As an organic material, coral is porous and requires careful handling.
Jasper: Jasper’s hardness ranges from 6.5 to 7 on the Mohs scale. Its specific gravity is typically between 2.60 and 2.65. Jasper lacks the brilliance of other gemstones, but its unique patterns and earthy tones make it appealing.
The following table summarizes these properties:
| Gemstone | Hardness (Mohs) | Specific Gravity | Key Characteristic |
|---|---|---|---|
| Opal | 5.5 - 6.5 | 1.98 - 2.50 | Play of Color |
| Tourmaline | 7 - 7.5 | 3.02 - 3.22 | Pleochroism |
| Coral | 3 - 4 | 1.26 - 1.34 | Organic Origin |
| Jasper | 6.5 - 7 | 2.60 - 2.65 | Unique Patterns |
Symbolism and Metaphysical Beliefs
Throughout history, these October birthstones have been imbued with various symbolic meanings and metaphysical properties.
Opal has been associated with purity, hope, and truth. Ancient Romans believed it symbolized love and beauty, referring to it as cupid paederos. Despite a period of superstition in the 19th century, where opals were considered unlucky for those not born in October, many ancient cultures, including the Chinese, viewed them as symbols of good fortune. Opal is also believed to enhance vision, boost cognitive abilities, and even offer glimpses into the future.
Tourmaline, particularly pink tourmaline, is often linked to compassion, open-mindedness, and forgiveness, earning it the nickname “Stone of Reconciliation.” Pink tourmaline is believed to boost energy, encourage love, and smooth relationship troubles.
Coral has long been considered a protective stone, warding off evil spirits and promoting vitality.
Jasper is believed to bring emotional stability and grounding energy. Its speckled appearance is thought to represent the earth’s energy and connection to nature.
Care and Cleaning
Due to their differing properties, each of these October birthstones requires specific care.
Opal, being relatively soft, is susceptible to scratches and should be stored separately from harder gemstones. Cleaning opal involves gentle washing with mild soap and warm water. Avoid ultrasonic cleaners and harsh chemicals.
Tourmaline is more durable and can be cleaned with warm soapy water and a soft brush. Ultrasonic cleaners are generally safe for tourmaline, but caution should be exercised with stones that have been treated or enhanced.
Coral, being an organic material, is porous and delicate. It should be cleaned gently with a soft cloth and mild soap and water. Avoid prolonged exposure to sunlight or heat.
Jasper is relatively durable and can be cleaned with warm soapy water and a soft brush.
Conclusion
October’s birthstones – opal, tourmaline, jasper, and coral – offer a rich tapestry of history, geological wonder, and symbolic meaning. From the ancient beliefs surrounding opal’s protective powers to the modern association of pink tourmaline with love and compassion, these gemstones continue to captivate and inspire. Whether chosen for their aesthetic beauty, their perceived metaphysical properties, or simply as a celebration of an October birthday, these gems hold a special place in the world of gemstones.