a. A white or gray chalcedony, opal, or massive quartz unevenly colored
by, or intergrown with, pink or reddish inclusions of cinnabar, the color
of which tends to become brown. The opal variety is know as opalite.
b. Cinnabar intergrown with common white opal or translucent chalcedony.
Dictionary of Mining, Mineral, and Related Terms