October boasts the unique distinction of having two recognized birthstones: opal and tourmaline. Both gemstones offer a remarkable diversity of colors and optical phenomena, making them captivating choices for those born in the tenth month of the year. While opal held sole claim for much of history, tourmaline was officially added as an alternative in 1912, solidifying its place as a cherished October birthstone. This article will delve into the history, geological origins, gemological properties, symbolism, and care of these fascinating gems.
History and Lore
The origins of associating gemstones with specific months are rooted in ancient traditions, initially linked to the zodiac rather than the calendar months as we know them today. The formalized lists of birthstones began to take shape in 1870 with a pamphlet published by Tiffany & Co., which initially designated opal as the sole birthstone for October. Prior to this, various cultures held different beliefs about the stones associated with particular months.
The name “October” itself derives from the Latin “octo,” meaning “eight,” reflecting its original position in the early Roman calendar, which consisted of only ten months. Anglo-Saxons referred to October as Winterfylleth, signifying the “winter full moon,” as they believed winter commenced during October’s full moon. Ancient Roman celebrations during October, such as Mundus Patet, involved a belief in the opening of realms between the living and the dead, a theme echoed in modern holidays like Dia de Los Muertos and Halloween.
Opal, in ancient times, was considered a symbol of purity, hope, and perspective. Romans poetically referred to opals as cupid paederos, translating to “child as beautiful as love.” Despite a period of superstition in the 19th century where opals were falsely believed to be cursed, many ancient civilizations, including the Chinese, regarded them as lucky stones. A lingering superstition persists that wearing an opal is unlucky for anyone not born in October.
Geological Formation and Sources
The provided sources do not detail specific geological formations or mining locations for either opal or tourmaline. However, they do indicate that tourmaline is a relatively widespread gem, found in a variety of colors. Opal, conversely, is noted for its unique play-of-color, a phenomenon dependent on its internal structure.
Gemological Properties
Tourmaline is a complex borosilicate mineral with a chemical formula that varies depending on its composition. Most tourmalines are classified as Type II clarity, meaning minor inclusions are typically visible. However, chrome and green tourmalines are often inclusion-free (Type I), while varieties like Paraíba, rubellite, and watermelon tourmaline consistently exhibit visible inclusions (Type III). The presence of aligned tubes causing chatoyancy, or a “cat’s eye” effect, can increase a tourmaline’s value. Tourmaline can even be found as an inclusion within quartz.
Opal is a hydrated amorphous form of silica. Its value is determined by its play-of-color, body tone, and pattern. The most valuable opals exhibit flashes of red, or a full spectrum of colors, with unique patterns covering the stone’s surface. Darker specimens, such as black opals, display brighter play-of-color. Full transparency is rare in opals, though desirable in some varieties. Cloudiness generally lowers an opal’s value.
Here's a comparative table summarizing key properties:
| Property | Tourmaline | Opal |
|---|---|---|
| Clarity | Type II (most), I & III | Typically opaque |
| Transparency | Variable | Rare (except fire opal) |
| Play-of-Color | Absent | Present (precious opal) |
| Inclusions | Common | Variable |
Symbolism and Metaphysical Beliefs
Both opal and tourmaline are imbued with symbolic meaning. Tourmaline, often called the “Stone of Reconciliation,” represents compassion, open-mindedness, and forgiveness. Pink tourmaline, in particular, is believed to boost energy, encourage love, and aid in resolving relationship issues. Each color of tourmaline is associated with specific healing properties.
Opal’s symbolism is linked to vision and the mind. It is believed to treat eyesight problems, enhance cognitive abilities, and even offer glimpses into the future. The name “opal” itself originates from the Greek word meaning “to see a change in color,” reflecting its characteristic optical effect.
Treatments and Value
Treatments can affect the value of both opal and tourmaline. Untreated opals, especially rare varieties like black opal, are significantly more valuable. Common treatments for tourmaline include irradiation, heat treatment, and fracture-filling, all aimed at improving color or clarity. These treatments generally lower a gemstone’s value.
The rarest and most valuable tourmaline variety is Paraíba tourmaline, known for its vibrant blue and green hues. Black, red, and pink tourmalines are more commonly found. Pleochroism, the display of different colors from different angles, is a prized characteristic in tourmaline, with strong pleochroism increasing value.
For opals, the value is heavily influenced by body tone and play-of-color. Black or red opals are the rarest and most valuable. The best play-of-color displays bright flashes of red or a full spectrum of colors, with unique patterns covering the stone’s surface.
Care and Cleaning
The sources do not provide specific care instructions for either opal or tourmaline. However, given tourmaline’s generally good hardness and resistance to chemicals, standard gemstone cleaning practices (warm soapy water and a soft brush) would likely be suitable. Opal, being a softer stone, requires more delicate handling to avoid scratches or damage.
Conclusion
October’s birthstones, opal and tourmaline, represent a captivating blend of history, beauty, and symbolism. From the ancient beliefs surrounding their mystical properties to the modern appreciation of their unique gemological characteristics, these gemstones continue to fascinate and inspire. Whether chosen for their aesthetic appeal, their perceived healing powers, or simply as a representation of an October birthday, opal and tourmaline offer a vibrant and meaningful connection to the natural world.