Minerals (By : Riztie's research)

                                Augite   A common rock-forming mineral of dark-colored igneous rocks. Augite is a  rock-forming mineral  that commonly occurs in mafic and intermediate  igneous rocks  such as  basalt ,  gabbro ,  andesite , and  diorite . It is found in these rocks throughout the world, wherever they occur. Augite is also found in ultramafic rocks and in some  metamorphic rocks  that form under high temperatures. Augite has a chemical composition of (Ca,Na)(Mg,Fe,Al)(Si,Al) 2 O 6  with many paths of solid solution. Commonly associated  minerals  include  orthoclase ,  plagioclase ,  olivine , and  hornblende . Augite is the most common pyroxene mineral and a member of the clinopyroxene group. Some people use the names "augite" and "pyroxene" interchangeably, but this usage is strongly discouraged. There are a large number of pyroxene minerals, many of which are distinctly different and easy to identify. Augite,  diopside ,  jadeite ,  spodumen

                 Arsenopyrite                                Mineral Properties and Uses What is Arsenopyrite? Arsenopyrite is an iron arsenic sulfide  mineral  with a chemical composition of FeAsS. It is the most abundant arsenic mineral and the primary ore of arsenic  metal . In addition to being found in deposits that are large enough to be minable, arsenopyrite is widely distributed. However, it usually occurs in such small amounts and in such small particle sizes that it is easily overlooked. It is associated with other sulfide minerals in organic-rich  sedimentary rocks ,  metamorphic rocks , and  igneous rocks  in many parts of the world. Geologic Occurrence Much of the arsenopyrite that has been mined formed as a high-temperature mineral in hydrothermal veins. It is often mined, together with other metallic minerals, from veins that might contain  gold ,  silver ,  lead , tungsten, or tin. In these deposits arsenopyrite usually occurs in a granular massive f

Apatite, Phosphorite and Phosphate Rock     What is Apatite? Apatite is the name of a group of phosphate minerals with similar chemical compositions and physical properties. They are an important constituent of phosphorite, a rock mined for its phosphorus content and used to make fertilizers, acids, and chemicals. Apatite has a relatively consistent hardness and serves as the index mineral for a hardness of five in the Mohs Hardness Scale . Specimens with excellent clarity and color are sometimes cut as faceted gemstones . Those with good color and translucence are cut as cabochons. Physical Properties Apatite is best known for its use as an index mineral with a hardness of 5 in the Mohs Hardness Scale. It is usually green in color, but can be yellow, brown, blue, purple, pink, or colorless. These colors are often so vivid that apatite has frequently been cut as a gemstone. Apatite is a brittle material. It breaks by both fracture and cleavage, but the cle

                             Anhydrite   An evaporite mineral used as a soil treatment and to produce construction materials     What is Anhydrite? Anhydrite is an evaporite mineral that occurs in extensive layered deposits in sedimentary basins where large volumes of sea water have been evaporated. It is typically interbedded with halite , gypsum , and limestone in accumulations that can be up to hundreds of feet thick. On a much smaller scale, anhydrite can form in shoreline or tidal flat sediments from the evaporation of sea water. Anhydrite also occurs as a vein-filling mineral in hydrothermal deposits. It is deposited from solution, often along with calcite and halite, as gangue in sulfide mineral deposits. Anhydrite is also found in the cap rock of salt domes and in cavities of trap rock. Anhydrite is an anhydrous calcium sulfate with a composition of CaSO 4 . It is closely related to gypsum, which has a chemical composition of CaSO 4 . 2H 2 O. The wor

                   Andalusite and Chiastolite   What is Andalusite? Andalusite is a rock-forming mineral that is mined for use in high-temperature refractories. Gem-quality specimens are cut into faceted gems and cabochons . Andalusite forms during the regional metamorphism of shale . It is found in schist and gneiss at some present and ancient convergent plate boundaries where the rocks have been exposed to the temperatures and pressures needed for its formation. In these rocks , andalusite is often associated with kyanite and sillimanite. Andalusite also forms during the contact metamorphism of argillaceous rocks. In this situation, it can form within the metamorphosed rock or in veins and cavities within the igneous rock. It can be associated with cordierite in hornfels , granite , and granitic pegmatite  From: https://geology.com/minerals/andalusite.shtml Andalusite is an aluminium nesosilicate mineral with the chemical formula Al₂SiO₅. Th