MINERALS

Definition: Naturally occurring, Inorganic, Solid, Crystalline, specific chemical composition, regular repeating atomic arrangement

Chemical Composition - specific ratio of chemical elements;
atom - smallest coherent unit of chemical element;
protons - have mass/weight, positive (+) electrical charge, defining characteristic of a chemical element;
neutrons- have mass/weight, no electrical charge;
electrons - no mass/weight, negative (-) electrical charge

Structure - in simplest case (equilibrium) #protons=#neutrons=#electrons;
nucleus- central core of the atom which contains all of the mass/weight of the atom - all of the protons and neutrons - positive electrical charge;
electron cloud or electron shells- made of electrons - no mass/weight - negative charge -form in shells which can hold a specific number of electrons - interior shells fill before electrons are added to outer shells - atom is most stable when outer shell is full
atomic number - # of protons, defining property of an element; gives the name/identity of the element, this number is unique to each element

Common elements in rocks: Si, Al, O, Ca, Mg, H, C, Fe, Na, K

Periodic table - elements listed in order of increasing atomic number;

normal equilibrium - #protons=#neutrons=#electrons;
ion - #protons=#neutrons but not equal to #electrons (has some electrical charge);
isotope - #protons but not equal to #neutrons

Crystal structure - regular repeating atomic arrangement
ionic bonds (+) and (-) charged ions attract; covalent bonds - elements share electrons in outer shell; metallic bonds - electrons float about so their electrical charge is distributed

silicate structure - SiO₄ tetrahedron, isolated tetrahedra, single chain, double chain, sheet, 3-D framework

silicate minerals, isolated tetrahedra -olivine (Fe, Mg); single chain - pyroxene (Fe, Mg); double chain - amphibole (Fe, Mg, Ca); sheet - mica; biotite (Fe, Mg) or muscovite (K); 3-D framework - Feldspar (Ca, Na, K); Quartz (SiO₂)

Non-silicate minerals- calcite (CaCO₃), halite (NaCl); gypsum (CaSO₄)

Physical properties-luster, color, crystal shape, cleavage, fracture, hardness, specific gravity, other (fizz, magnetism, double refraction...)

Relate the following to each other: protons, neutrons, electrons, atomic number. What is the defining characteristic of an element?

How is the location of an element on the periodic table related to the number of orbitals it contains? the number of electrons in the outermost orbital? How is chemical bonding sometimes related to the position of elements in the table?

How do ions and isotopes relate to the equilibrium state of an element? Which is electrically charged?

Be able to identify a sketch of a silica tetrahedron, a single chain, a double chain, and a sheet structure. Give an example of a mineral which contains each type of structure.

Describe six techniques used in identification of an unknown mineral. Which are the most useful?

Carefully define mineral. How does this relate to rocks? elements?  Characterize the difference between a mineral and natural glass.

Why does the silica tetrahedron have the composition SiO₄ while quartz is SiO₂?

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