The name opalite was defined as common opal in geology and gemology glossaries as early as 1945. This predates the use of the word opalite as a marketing term for an imitation opal. It is defined as a natural common opal that does not show play-of-color. (The first use of the word opalite as a marketing term for man-made materials occurred in the 1980s.)

Common opal is found in many locations throughout the world. Most of it is a white to yellow to brown material that is usually not considered for use as a gem. However, some specimens of natural common opal have a wonderful color, accept a bright polish, and can be cut into highly desirable gems.

Play-of-color is not needed for common opal to be used as a gem material. Some transparent specimens of common opal have a color and clarity that makes them worthy of being cut into faceted gems.