Coloring is similar and the hardness is not far apart. Without special testing equipment, distinguishing it from a natural diamond, is very difficult if not impossible. Green color is soon to be released and available. Triplet Opals are frequently created as triplets, meaning the stone is assembled from three pieces. Opal triplets are composed of a rock quartz layer over genuine opal joined to a base.
Triplets resist marring, and the quartz acts to play up the brilliance of the genuine stone.
Step One Wrap a piece of string or a strip of paper around your finger. Step 2 Mark the point where the two ends meet. Step 3 Measure the string or paper against a ruler.