feldspars
41silica mineral — Any of the forms of silicon dioxide (SiO2), including quartz, tridymite, cristobalite, coesite, stishovite, melanophlogite, lechatelierite, and chalcedony. Various kinds of silica minerals have been produced synthetically. * * * Introduction… …
42silicate mineral — Any of a large group of silicon oxygen compounds that are widely distributed throughout much of the solar system. The silicates make up about 95% of the Earth s crust and upper mantle, occurring as the major constituents of most igneous rocks and …
43Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
44chemical element — Introduction also called element, any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed. This article considers the… …
45Common rock-forming minerals — ▪ Table Common rock forming minerals quartz calcite biotite hematite alkali feldspars dolomite muscovite limonite plagioclase feldspars clay minerals amphibole …
46feldspar — noun Any of a large group of rock forming minerals that, together, make up about 60% of the earths outer crust. The feldspars are all aluminum silicates of the alkali metals sodium, potassium, calcium and barium. Feldspars are the principal… …
47Charnockite, St. Thomas Mount — Coordinates …
48Al2O3 — Alumina A*lu mi*na, n. [L. alumen, aluminis. See {Alum}.] (Chem.) One of the earths, consisting of two parts of aluminium and three of oxygen, {Al2O3}. [1913 Webster] Note: It is the oxide of the metal aluminium, the base of aluminous salts, a… …
49Alumina — A*lu mi*na, n. [L. alumen, aluminis. See {Alum}.] (Chem.) One of the earths, consisting of two parts of aluminium and three of oxygen, {Al2O3}. [1913 Webster] Note: It is the oxide of the metal aluminium, the base of aluminous salts, a… …
50aplite — n. 1. light colored and fine grained granitic rock consisting chiefly of quartz and feldspars. [WordNet 1.5] …
