Individual opals can vary widely in appearance and quality. As diverse as snowflakes or fingerprints, each gem can differ noticeably from the next, even those from the same mine. On the other hand, entire parcels of low-end opal can look virtually identical.
An opal’s appearance typically changes with lighting or viewing angle. A single opal can display a shift in play-of-color and pattern, depending upon the time of day, the weather, or the way the stone is tilted or turned. This changeable nature makes it challenging for experts to classify and evaluate opal consistently. In simplest terms, three aspects combine to create an opal’s unique beauty.
Color – Background color and play-of-color
Patter – Arrangement of play-of-color
Clarity – Transparency and amount of inclusions
Photo: Duncan Pay Courtesy: GIA. Resource: Amanda. #eClarity