Chapter 9 Minerals Matter – anything w/ volume and mass 3 states of matter… Solid – Little kinetic energy –tight particles Liquid – middle kinetic energy – loose particles Gas – lots of Kinetic Energy – spaced particles Elements – building blocks of minerals Can’t be broken down into simpler substances by chemical/physical means 112 elements; approx. 4000 minerals

Periodic Table Each element represented by 1-2 letters 8 elements make up most of earth’s crust. Metals – malleable, ductile, good conductors of heat/electricity left side of periodic table Non-metals – brittle and poor conductors right side of the periodic table

Atoms Atom – the first man! Atom – smallest particle of matter that contains the characteristics of the element Are neutral (no charge) Equal #s protons and electrons

Atom Parts Protons – positively charged Neutrons – no charge (neutral) 1 amu = mass Found in nucleus Neutrons – no charge (neutral) Electrons – negatively charged Very little mass Outside of nucleus in energy levels

Atomic number – # of protons in the nucleus Sequentially numbered Mass number - # of protons and neutrons in the nucleus Isotope – atom with same # of protons but a different # of neutrons Used for dating rocks/fossils EX: 12C and 14C Ion – atoms that gained or lost electrons giving them a charge (+ or -)

Mixtures, Solutions, Compounds Mixture – combination of substances… Don’t lose identities (of components) Easy to separate components Not in a set ratio Solutions – special type of mixture Compounds – 2 or more elements chemically combined Components lose their identity Components can’t be separate out easily Components in a specific, set ratio

Atomic Bonds (James) Atoms without a full outer energy level are likely to bond chemically. 3 types: Ionic – formed when electrons are transferred from a + ion to a – ion - between metals and non-metals Covalent – when electrons are shared between the atoms of non-metals Metallic – when electrons are shared by metal ions.

Minerals 5 characteristics Naturally occurring (not man-made) Solid at normal surface temperatures Inorganic (not from living things) Definite and orderly crystal structure Definite chemical composition

Mineral Formation Crystallization from magma Precipitation from water From cooling magma Precipitation from water Like evaporated salt water Pressure and temperature Forms new minerals (metamorphism) Hydrothermal solutions From hot solutions

Mineral Groups Silicates Non silicates Most common group Must contain silicon and oxygen Silicon-oxygen tetrahedron (SiO4) Non silicates Cannot contain both silicon and oxygen Much less common 6 subgroups Carbonates, oxides, sulfates, sulfides, halides, native elements

Mineral Properties Color – its color! Poor test alone Minerals may be many colors Many minerals can be the same color Streak – color of the powdered mineral Produced by rubbing mineral on the streak plate Cleavage – tendency of a mineral to cleave (split) along flat, even surfaces Fracture – jagged, uneven breaking of a mineral

Mineral Properties Luster – the way light reflects from its surface… Metallic – Non-metallic – Glassy (vitreous) Pearly Earthy Greasy waxy

Mineral Properties Crystal form – geometric shape of minerals Density – the ratio of its mass to its volume Hardness – resistance of a mineral to being scratched, like, dude, scratchability Moh’s hardness scale – from 1 – 10 See table page 52 Fingernail = 2.5 Penny = 3.5 Glass plate = 5.5 Streak plate = 7

Unusual Mineral Properties Taste – salty (halite) Smell – rotten eggs (sulfur) Feel – greasy/slick (talc, graphite) Writes on paper – (graphite) Magnetic – magnetite (lodestone) Radioactive – triggers a Geiger counter, (uranium) Reactive – reacts with HCl acid (calcite) Double refraction – see 2 images through it (calcite & Icelandic spar) Optical fiber – can see through it (ulexite = TV rock) Fluorescent – changes color under UV light (fluorite) Gemstones – precious or semi-precious, page 56/57