The mineral heliotrope, also known as bloodstone, is a form of chalcedony (which is a cryptocrystalline mixture of quartz and its monoclinic polymorphmoganite). The "classic" bloodstone is green chalcedony with red inclusions of iron oxide or red jasper. Sometimes the inclusions are yellow, in which case the mineral is given the name plasma. The red inclusions are supposed to resemble spots of blood; hence the name "bloodstone". The name "heliotrope" derives from various ancient notions about the manner in which the mineral reflects light. The primary source of the stone is India. It is also found in Brazil, China, Australia and the United States. There is also an outcrop of bloodstone on the Isle of Rum, in Scotland. Heliotrope as raw material and as artefacts from the Chalcolithic sites (5th millennium BC) has been found in the Eastern Rhodopes of Bulgaria.