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General Geology: Minerals. Instructor: Prof. Dr. Boris Natalin. Topics. Minerals versus rocks Composition of minerals S tructure of minerals M ineral groups C ommon minerals. Natural diamond crystal . A rock A mineral. Rocks is an aggregate of one or more minerals. Minerals.
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General Geology: Minerals Instructor: Prof. Dr. Boris Natalin
Topics • Minerals versus rocks • Composition of minerals • Structure of minerals • Mineral groups • Common minerals
Natural diamond crystal • A rock • A mineral
Minerals • 3500 – 4000 minerals are uniquely defined by their chemical composition and internal (atomic structure) • Only 70 minerals are widespread • Rock-forming minerals
Periodic Table of Elements Some minerals are made of one element but the majority is a combination of two or more elements
Composition of minerals • Atom nucleus • Orbiting electrons • Energy levels of electrons
Bounding in compounds • Compound – two or more elements bounded together • Bound or chemical bound • Octet rule • Valence electrons
Bounding in compounds Ionic bounding Covalent bounding in chlorine (Cl2)
Polymorph Diamond Graphite
Identification of minerals • Physical properties: - Crystal forms - Luster - Color - Hardness - Cleavage - Density
Cleavage Muscovite KAl2(AlSi3O10)(OH2)
Halite Cleavage Calcite Fluorite
Density Gravity Galena
Mineral groups • Classification: mineral species – mineral classes (anion complexes e.g. SiO4-, CO2-) – mineral groups (similarity of atomic structure)
Silicate Silicon-oxygen tetrahedron SiO4 (SiO44-)
Chemical formula • (Mg, Fe)2SiO4 – olivine • Family of minerals : from Mg2SiO4 – to – Fe2SiO4
Silicate minerals • Ferromagnesian silicates • Nonferromagnesian silicates
Nonferromagnesian silicates • Muscovite • Feldspar: Orthoclase Plagioclase • Quartz