ERTH 2404 Lecture Notes - Lecture 2: Potassium Feldspar, Clay Minerals, Continental Crust
22 Mar 2017
School
Department
Course
Professor
Document Summary
Inorganic, naturally occurring: classiied according to chemical composition and internal structure, polymorphs: minerals with the same chemical composition but diferent crystalline structure diferent properties. Metamorphic (igneous and sedimentary: monomineralic: composed of 1 mineral, polymineralic: +1 mineral. Crystalline structure: array of atoms based on arrangement of bonds. Van der waals: weak attraction b/w planes: crystal: macroscopic expression of the crystalline structure, diferent lattice arrangements = diferent mineral name, polymorphs, ex. Mineral classiication: due to planetary diferentiation, there are 8 elements that compromise 98% of earth"s crust: si and o are 75, 1. Silicate group is subdivided by the way in which unit interacts within the structure. Four available oxygen ions surrounded by smaller si ion. Single chains: pyroxenes ***** not amphiboles, mg-fe series: orthopyroxene, ca-mg-fe: clinopyroxene. Two dimensional sheet silicates: distinctly layered crystals, layers peel apart. Excellent cleavage is developed along the planes of the individual layers: another aspect: clay minerals, variety of complex minerals.
