In addition, an opal’s play-of-color can change along with the viewing angle or type of light. However, favored colors can vary with fashion or personal preference. Traditionally, red is considered the best prominent color, orange the next most desirable, followed by green. Courtesy Cody Opalĭesirable play-of-color is further broken down by the colors themselves. These light-colored opal beads are milky in appearance and have numerous dead spots with no play-of-color. This material, which might show play-of-color, is also known in the trade as “Mexican opal” or “Mexican fire opal”. Additionally, black opals are considered to be the rarest (white opals are more common).Īn opal with a translucent to opaque white and other light color backgrounds (bodycolor) with play-of-color is called white opal.įire opal is transparent to translucent with a bodycolor that is usually yellow, orange or red. The contrast of play-of-color to bodycolor makes black opals very popular. This is partly because play-of-color tends to stand out attractively against a dark background. Even though there are many different categories for opals, here are the main five types:Īll other quality factors being equal, many buyers favor the dark background color of black opal. Opals are often divided into types based on background color. Courtesy Mariora, Surfer’s Paradise, Australia This black opal has a lot of red play-of-color, which is considered highly desirable. Background color-also called bodycolor-is caused by the suspension of tiny impurities within opal’s silica spheres. Opal displays background color in addition to play-of-color. An opal might display a single color, two or three colors, or all the colors of the rainbow. Look for the presence of matrix, crazing, pits, etc.Ĭonsider the opal’s symmetry, thickness, polish, sizing and calibration. Is it transparent, semi-transparent, translucent, semi-translucent or opaque? Is it a black opal, white opal, crystal opal, etc.?ĭetermine the ratio and quality of its play-of-color:Ĭonsider the percentage of play-of-color compared to background color, its intensity, dominant hues, range of color and pattern. Rotating the opal against a background helps when you’re determining its type and evaluating its play-of-color and cut. Opal evaluation should be done under controlled lighting on a dark background. Clarity-Transparency and quantity of inclusions.Color-Background color and play-of-color.There are three main aspects of an opal’s quality: As diverse as snowflakes or fingerprints, each gem can differ noticeably. Individual opals can vary widely in appearance and quality. Small play-of-color flashes of orange and green predominate in a pinfire pattern, with spots of a more muted blue over a grayish bodycolor. This large Australian light opal cabochon weighs 117.85 carats. Comprehensive CAD/CAM For Jewelry Certificate
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