Lecture 1

Earth Materials - Minerals and Rocks

Overview Details

Minerals: basic compounds of the solid earth. ~ 3000 known; these 3000 contain all of the chemical elements of which the earth is made.

Rocks: physical mixtures of minerals. Most of the rocks that make up the earth are composed of only ~ 50 of the known minerals

Why study? Minerals occur in nearly all inorganic materials of everyday life, and are thus important economically, aesthetically and scientific terms.

Definition of a mineral:

A mineral is a naturally occurring, inorganic, homogeneous solid with a definite chemical composition and an ordered atomic arrangement

The crystalline state of matter is the most fundamental property of minerals

Aspects of Earth Materials that we will cover this term:

- crystal chemistry - the chemical nature of minerals

- crystallography - the study of symmetry and the internal order of crystals

- mineral physics - the physical properties of minerals

- petrology – the study of rocks and the minerals that form them

A bit of history

The history overview is just for fun and background inter. Symmetry and form of a crystal are determined by the shape of that unit cell. The chemical formula of a mineral expresses the relative proportions of its constitutive elements.