Translucent white glass developed in 17thC Venice and later made throughout Europe. It was particularly popular in Britain during the 19thC for cheap ornamental wares. translucency was achieved by adding bone ash to the molten glass. When held up to the light, the glass shows slight reddish tones.

a milky white translucent or opaque glass

Glass that resembles an opal, being translucent and white, with a grayish or bluish tint.

Opal glass is a milky white glass that mimics opals.

A milky looking glass used to diffuse light. (See Diffuse Lighting).

Diffuser comprised of glass plate with white coating approximately 1 mm thick. With low on-axis transmission, scattered percentage is high off-axis and evenly diffused light is produced. It is also often used as a target (i.e. for lasers). Transmission data as a function of angular diffusion is currently not available for opal and diffused glasses. See also Ground Glass.