How the Cut of the Opal Affects its Value
Precious opal is almost always cut in cabochon. The most valuable cut is usually a domed cabochon. High domes are desireable for crystal opal and more shallow domes are the norm for black opal.
The shape of the cut can play a role in determining the value. More symmetrical cuts are usually more expensive than irregular “free form” shapes. Very precious opal is often cut in free form shapes to avoid cutting away valuable material.
Finally, the finish and the polish of the opal also affects its value. Rough spots, dull spots, small cracks, pits or chips will diminish the value of the opal.
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