Types of Coal and Coquina
Some rocks according to their use or texture are classified into different types. Know more about Coal Texture and Coquina Texture. Types of Coal are Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite whereas the types of Coquina are Not Available.During historic times, some rocks depending on their hardness were used to create Pictographs and Petroglyphs. Rocks which are hard were generally not used. Pictographs are paintings or drawings that have been placed or created on the surface of rock. Coal was not used to create pictographs whereas Coquina is used to create pictographs. Petroglyph is an image which is carved into a rock. These are images created by removing part of a rock surface by incising, picking, carving or abrading, as a form of rock art. Coal was not used to create petroglyphs whereas Coquina was used to create petroglyphs.