Heliotrope (mineral) 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 ancient notions about the manner in which the mineral reflects light. These are described, e.g., by Pliny the Elder ("Nat. Hist." 37.165). Heliotrope was called "stone of Babylon" by Albert the Great and he referred
Non-metallic inclusions During deformation, which occurs from flatting, forging, and stamping, non-metallic inclusions can cause cracks and fatigue failure in steel. When investigating the influence of non-metallic inclusions on the quality of steel, of great importance are the properties of these inclusions: size, shape, chemical and physical characteristics. All these properties depend on the chemical composition of steel, method of smelting and for certain steel grade. These properties can change within wide limits even within the same mode of production. Different methods for analysis of non-metallic inclusions have been developed and are now in use. These make it possible to determine content,