The term Crystal Opal refers to a transparent or semi-transparent opal.
If the back of a crystal opal is enhanced, it looks a lot brighter, but these have to be called \“solid enhanced crystal opals.\”
Blue crystal opals are most the common crystal opals. Rarer is orange, with sunset red the rarest fire crystal colour. Most opal fields include crystal opal, as it is formed with no base (like potch or ironstone or sandstone) and is appreciated for its rarity and unique colour patterns.
Source your single-gem crystal opals or parcel crystal opals direct from opal miners and opal wholesaler/dealers from Lightning Ridge, Australia.