SPECULARIS Lapis, composed of large plates of extreme thinness. (See TALC, MINERALOGY Index). The white variety with large and broad leaves, commonly called Jinglafis and Mufcory glafs, is imported in great quantities; the miniature-painters cover their pictures with it; the lantern-makers sometimes use it instead of horn; and minute objects are usually preserved between two plates of it, for examination by the microscope.