At Omi Privé we covet black opal from the Lightning Ridge area of New South Wales, Australia. As gemologists we are taught never to identify gemstones by sight alone, but when it comes to natural opals, there’s nothing that quite compares and there are no two opals that are exactly alike. There are certain patterns that appear more often than others in the play-of-color seen in opals.
Opal is a non-crystalline form of the mineral silica. It is formed when tiny spheres of silica solidify and stack on top of one another. The uniformity of size of these spheres helps determine how the opal diffracts light and what color appears. Generally, when the spheres are more uniform in size and arrangement, the opal will produce more intense and defined play of color.
No two opals are alike, which is why developing a catalogue of patterns to help gemstone dealers and jewelers more accurately describe the stone is important. It’s common for opals to display one or more of these patterns throughout the stone, but generally, those with larger, more saturated and distinct patterns throughout will be more valuable. At Omi Privé we love celebrating this magnificent gemstone with vibrant and unusual color combinations and accents that emphasize the phenomenal nature of the opal; here we will take a closer look at some of these pattern names as seen in Omi Privé pieces:
Pinfire: Seen in these opal rings – pinfire patterned opals can be described as having small bright spots of different colors that punctuate the stone and are visible in all directions.
Sheen & Moss: Sheen and moss patterns can be observed in this opal pendant. Sheen is considered as an overly similar, matching color pattern with diffuse, undefined flashes. It would also classify as a moss pattern which is just as it sounds; the play of color resembles scrawling moss.
Flash: The flash pattern in opals can appear in different ways. A broad flash pattern will cover a substantial part of the face of the opal, usually as a single color. Rolling flash patterns will roll across the face of the stone as it’s moved. Below are two examples of flash pattern opals.
Flagstone Harlequin: Harlequin patterns are often the most rare and valuable of all opal patterns, and are defined by a pattern of repeating squares of color. There are varieties of this pattern, and one is the flagstone harlequin, which contains patches of color that are more irregular in shape and fit together in a mosaic style similar to flagstone paving.
Clover Harlequin: Similar to the above flagstone harlequin pattern, clover harlequin opals will display units of color that form in a clover leaf-like design.
Chaff: Opals with chaff patterns will often display other patterns as well, but the chaff pattern is observed when randomly oriented patches of color are broken by fine lines or brushstrokes crosshatching in different directions.
Ribbon: Seen below in this exquisite opal, this pattern is observed as “ribbons” of color that will run across the opal, generally parallel from one another.