This video will see the opal body tone and brightness grading system used by opal sellers worldwide. I use real opals to show you a hands-on feel to the way the scale works.
This scale is small so that you’re able to take it anywhere. To grade your opal, slide it along the N scale and find the box where the body tone fits best. Next, slide your opal along the brightness scale while moving it back and forth to see where it best sits. After that, you can measure your opal on the side in millimetres.
There you go; you’ve just graded your opal!