Spectrum Sierra Red Pearl Opal Glass has a vibrant pearl color with dynamic depth. It is an easy-to cut art glass.
In Spectrum opal and opalescent glass a material has been introduced at the raw materials stage (usually fluorine or phosphorus) which causes a degree of crystallization to occur, and creates opacity in the glass. Reflected light is colorless, therefore white. The degree of opacity (and "whiteness") is variable depending upon composition and temperatures used in the manufacturing process. Commonly then, white glass is called "opal."
- Solid Color Opalescent Glass: Glass which is both colored and crystallized, creating a single color sheet, more opaque than a cathedral. Sometimes called "opaque" glass.
- Mixed Opalescent Glass: White glass (opal) mixed with one or more other colors to create a variegated, multi-colored sheet. Light transmission varies with composition. Also called "variegated opalescent," sometimes "streaky."