October’s gemstone is one of the most mesmerizing on Earth: the opal. No two opals are exactly alike, and that unique character is what has made this unusual gem a source of fascination for centuries.
Its name stems from the Sanskrit word upala, meaning “jewel” or “precious stone.” Ancient Romans considered it the most precious and powerful of all gems, as it seemed to hold the colors of many other gemstones all at once. Bedouin tradition held that opals contained lightning and fell from the sky during thunderstorms.
What makes opal unique is its “play-of-color”, with flashes of rainbow light that shift as the stone moves, an effect caused by the diffraction of light through tiny silica spheres stacked inside. The size of these tiny spheres determines the colors you see; with larger spheres producing prized red flashes.
When evaluating an opal, the most important value factors are its play-of-color, color intensity, and pattern, along with its size and cut. Opal is made of hydrated silica and can contain up to 20% water within its structure, which additionally makes it quite different from other gemstones.
Australia supplies the vast majority of the world’s opals, with other significant secondary deposits found in Ethiopia, Mexico, Brazil, and the United States. Available in several varieties, Black Opal features a dark or black body tone, making it the rarest and most valuable variety, while White Opal displays a translucent light or white background color. Boulder Opal is cut to include a portion of the natural ironstone matrix attached to the back of the gem and is vivid blue to green in color palette. Fire Opal is perhaps the most unusual, with its bright yellow to orange tones.
With a hardness of 5 to 6.5 on the Mohs scale, opal is much softer than many other popular gems and deserves gentle cleaning, handling, and storing. Pieces such as pendants and earrings are less exposed to impact or scratches than rings worn every day. Diamonds On The Key offers an array of ready-to-wear pieces, or select a magical loose opal, in your preferred color, and let us create a custom piece!
Whether you love it for its history or endless play of color, opal is a birthstone like no other, as unique as the person who wears it.
Christina Termine is the owner of Diamonds On The Key, a private jewelry salon available by appointment only. For more, contact (305) 851-1460.