Heliotrope (mineral) is Indonesia, especially in Purbalingga district. It is also found in Armenia, Azerbaijan, Brazil, Bulgaria, China, Australia, and the United States. There is also an outcrop of bloodstone on the Isle of Rum, in Scotland. Heliotrope (mineral) The mineral aggregate heliotrope (from Greek ἥλιος, "hḗlios" “Sun”, τρέπειν, "trépein" “to turn”), also known as bloodstone, is a variety of jasper or chalcedony (which is a cryptocrystalline mixture of quartz). The "classic" bloodstone is green jasper (chalcedony) with red inclusions of hematite. The red inclusions are supposed to resemble spots of blood, hence the name "bloodstone". The name "heliotrope" derives from various
Mineral alteration form the mineral pyrite. Opalization is the alteration of amorphous silica, often as organic remains of siliceous microfossils in lithified sedimentary rocks, into the mineraloid opal. Uralitization is the process of deuteric alteration of pyroxene (most commonly augite) to form amphibole (actinolite-tremolite). The alteration occurs during either late-stages of magmatic crystallization at low temperatures (< 500 °C) or during low-grade metamorphic events (sub-greenschist facies metamorphism). The reaction is paramorphic, meaning that the structure of the mineral is modified, but its original chemistry is retained. Mineral alteration Mineral alteration refers to the various natural processes that alter a mineral's chemical composition