Red Jasper is opaque, fine-grained or dense variety of the silica mineral chert. Jasper, long used for jewelry and ornamentation, has a dull lustre but takes a fine polish. Its hardness and other physical properties are those of quartz. In ancient writings the term jasper was chiefly applied to translucent and brightly colored stones, particularly chalcedony, but also was applied to the opaque jasper. Red Jasper was known as the great "rain-bringer" in the fourth century.