October is uniquely blessed with not one, but two recognized birthstones: opal and tourmaline. Both gemstones offer a stunning array of colors and a rich history, making them captivating choices for those born in the tenth month. While opal holds the distinction of being the traditional October birthstone, tourmaline was added in 1952 by the National Association of Jewelers to provide a wider selection and address perceptions of opal’s femininity and durability. This article will explore the origins, properties, lore, and significance of both these vibrant gems.
A History of Recognition
The designation of official birthstones is a relatively modern practice. The standardization of birthstones by the National Association of Jewelers in 1952 aimed to promote sales and provide a consistent guide for gift-giving. Prior to this, various cultures and traditions associated different gemstones with specific months, often based on astrological beliefs or availability. Opal, however, has a long and storied history predating its formal recognition as an October birthstone. Its origins can be traced back to ancient India, where it was known as upala, meaning “precious stone,” and later adopted as opalus by the Romans. Tourmaline’s history is somewhat more complex, often being mistaken for other gems due to its diverse color range.
The Allure of Opal: Iridescence and Lore
Opal is renowned for its unique optical phenomenon known as “play-of-color.” This captivating display of shifting rainbow hues distinguishes it from nearly all other gemstones. The dramatic play-of-color has inspired comparisons to fireworks, galaxies, and volcanoes, reflecting its dynamic and ethereal beauty. Bedouin tribes once believed opals contained lightning and fell from the sky during thunderstorms, while ancient Greeks associated the stone with prophecy and protection from disease. Europeans traditionally viewed opal as a symbol of purity, hope, and truth, believing it embodied the virtues of all colored stones.
Historically, opal was mined in diverse locations, including Ethiopia and Australia, with each region contributing to the gem’s distinctive character and hues. It is also the traditional stone given to celebrate the 14th wedding anniversary.
Tourmaline: A Spectrum of Possibilities
Tourmaline stands out for its unparalleled range of colors. The name itself is derived from the Sinhalese word toramalli, meaning “stone with mixed colors.” This gem can be found in vivid blues, reds, greens, and even combinations of colors, such as the striking “watermelon tourmaline” displaying both pink and green. The rarest and most prized variety is Paraíba tourmaline, a copper-bearing gem from Brazil known for its intense violet-blue and blue-green shades.
For centuries, tourmaline was often misidentified as other gemstones due to its diverse coloration. A notable example is the “Caesar’s Ruby” in the Russian crown jewels, which is, in fact, a red tourmaline (rubellite). Green tourmaline crystals discovered in Brazil during the 1500s were initially mistaken for emeralds. It wasn’t until the 19th century that tourmaline was formally recognized as a distinct mineral species.
Gemological Properties: A Comparative Look
While both opal and tourmaline are beautiful gemstones, their gemological properties differ significantly.
Opal is characterized by its amorphous structure, meaning it lacks a defined crystalline form. Its play-of-color is caused by the diffraction of light through microscopic silica spheres within the gem. Opal typically ranges from 5.5 to 6.5 on the Mohs hardness scale, making it relatively softer and more susceptible to scratching than tourmaline.
Tourmaline, on the other hand, is a crystalline borosilicate mineral. Its hardness ranges from 7 to 7.5 on the Mohs scale, making it more durable and suitable for everyday wear. Some tourmaline varieties exhibit piezoelectricity, meaning they generate an electrical charge when pressure is applied – a property that has been utilized in pressure gauges for submarines.
The following table summarizes key gemological properties:
| Property | Opal | Tourmaline |
|---|---|---|
| Chemical Formula | Hydrated Silica (SiO₂·nH₂O) | Complex Borosilicate |
| Crystal System | Amorphous | Trigonal |
| Hardness (Mohs) | 5.5 - 6.5 | 7 - 7.5 |
| Specific Gravity | 1.98 - 2.15 | 3.02 - 3.22 |
| Optical Phenomenon | Play-of-Color | Variable |
Symbolism and Metaphysical Beliefs
Both opal and tourmaline have been attributed with various symbolic meanings and metaphysical properties throughout history.
Opal has long been associated with hope, purity, and truth. It was believed to bestow the gift of prophecy and protect against disease. In modern times, opal is often seen as a stone of inspiration and creativity.
Tourmaline’s symbolism varies depending on its color. Black tourmaline is believed to protect against negativity and enhance self-confidence, while pink tourmaline embodies compassion and gentleness. Green tourmaline is thought to promote courage, strength, and stamina. Ancient mystics believed tourmaline could inspire artistic expression, and the last empress of the Chi’ing Dynasty in China was a passionate collector of vivid pink and magenta tourmalines, even being laid to rest on a tourmaline pillow. Tourmaline is also associated with the eighth wedding anniversary.
Care and Cleaning
Due to their differing hardness levels, opal and tourmaline require different care routines.
Opal is relatively soft and prone to scratching. It should be stored separately from harder gemstones to avoid abrasion. Cleaning opal involves gentle washing with mild soap and warm water, avoiding harsh chemicals or ultrasonic cleaners. Opals can also dehydrate and crack if exposed to prolonged heat or dryness, so it’s important to keep them hydrated.
Tourmaline is more durable and can withstand more rigorous cleaning. It can be cleaned with warm soapy water, a soft brush, and rinsed thoroughly. Ultrasonic cleaners are generally safe for tourmaline, but caution should be exercised with stones that have been fracture-filled.
Conclusion
October’s dual birthstones, opal and tourmaline, represent a captivating spectrum of color, history, and symbolism. Opal, with its iridescent play-of-color, embodies hope and inspiration, while tourmaline, in its diverse hues, offers a range of energies from protection and confidence to compassion and creativity. Whether chosen for their aesthetic beauty, historical significance, or metaphysical properties, these gemstones offer a unique and meaningful connection to the tenth month of the year.