This page provides a brief outline of, lists the main points of, gives links to figures for, and lists the assigned reading for a lecture in Dr. Bruce Railsback's GEOL 1121 class at the University of Georgia. This page is not intended as a set of lecture notes, and it cannot subsititute for a set of lecture notes. Familiarity with this page alone will not assure satisfactory grades on exams in the course.

Lecture 4 (Monday, January 14): Minerals

Brief outline of this lecture:
Definition of a mineral
   Crystallinity
   Chemical Composition
Properties of Minerals
   Physical Properties
   Other Properties
Chemistry of Earth's Crust, and its implications for mineralogy
Non-silicate minerals

Main points of this lecture:
A mineral is a naturally occurring inorganic crystalline solid with set chemical composition and characteristic physical properties.
Minerals are identified by physical evidence about them, which includes their physical properties, their reactions with other chemicals, and their transmission of electromagnetic radiation.
The bulk chemistry of earth's crust dictates that most minerals get their negative charge from oxygen or sulfur (and mostly oxygen).
The bulk chemistry of earth's crust dictates that most minerals are oxides, silicates, sulfates, sulfides, halides, and carbonates.
Virtually all of the natural solid non-living material on earth is crystalline minerals, whether as macroscopically visible crystals (rare except in rock & mineral shops) or as microscopic crystals in rocks and soils (much more common).
Some chemical substances can take two or more mineral forms and thus be polymorphic.
Some minerals form most commonly from the evaporation of seawater and so are called "evaporites".

Illustrations used in this lecture:
A definition of a mineral, and some mineral properties
Simple crystal models
The chemical compositon of the crust
Some non-silicate minerals

Reading assignment: pp. 25-31; 32-34; first part of p. 525.


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Email to Railsback (rlsbk@gly.uga.edu)
Railsback's main 1121 web page
Railsback's main web page
UGA Geology Department web page