Opalescent Glass Butterflies. The term “opalescent glass” is commonly used to describe glass where more than one color is present, being fused during the manufacture, as against flashed glass in which two colors may be laminated, or silver stained glass where a solution of silver nitrate is superficially applied, turning red glass to orange and blue glass to green. Some opalescent glass was used by several stained glass studios in England from the 1860s and 1870s onwards, notably Heaton, Butler and Bayne. Its use became increasingly common. Opalescent glass is the basis for the range of glasses created by Tiffany. Reference: Wikipedia
Below are some examples of opalescent glass objects with butterflies as part of their design.