rocks minerals 06

Rocks and Minerals• Atoms, Elements, Isotopes, Ions, and Compounds • Minerals–General • Types of Minerals • Rocks... Rocks and Minerals• Minerals Defined • Identifying Characteristics o

Rocks and Minerals

• Atoms, Elements, Isotopes, Ions, and

Compounds

• Minerals–General

• Types of Minerals

• Rocks

Minerals- the building blocks

• Atomic Structure

• Elements and Isotopes

• Ions

• Compounds

Rocks and Minerals

• Minerals Defined

• Identifying Characteristics of Minerals

• Other Physical Properties of Minerals

Halite Crystal

Source: Photograph © The McGraw-Hill Companies, Inc./Bob Coyle, photographer.

Galena

Source: Photograph © The McGraw-Hill Companies, Inc./Doug Sherman, photographer.

Halite

Definition of a Mineral

“A naturally occurring, inorganic, solid element or compound with a definite chemical composition and a regular internal crystal structure.”

Cubic Structure of Halite

Source: Photograph © The McGraw-Hill Companies, Inc./Bob Coyle, photographer.

Mineral Properties

• Hardness (Mohs hardness scale)

– See appendix C

• Cleavage (how it breaks- atomic scale)

• Luster- the surface ‘sheen’

• Color is not a good property for i.d.

– Corundum (Al 2 O 3 )

Minerals: two groups

• Silicates (Si + O ± other elements)

– All built with ‘silicon tetrahedra’

– 4 O atoms, 1 Si atom, 4 - charge

Minerals: non-silicates

• Nonsilicates Example

– Halides (metal + halide): salt (halite)

Definition of a Rock

• A solid, cohesive aggregate of one or

more minerals or mineral materials

• Important for construction

• Geologic history

The Rock Cycle

• Earth as a constantly changing system

The Rock Cycle

• Igneous Rocks

– Formed by the crystallization of magma

– Usually made up of silicate minerals

– Plutonic: solidified inside Earth (granite) – Volcanic: solidified on Earths surface (lava)

Granite, a Plutonic

Rock

Source: Courtesy of Carla W Montgomery

Obsidian,

Volcanic

Glass

Basalt, a Volcanic

Rock

Source:Courtesy of Carla W Montgomery

Porphyry, an

Igneous Rock

The Rock Cycle

Limestone

Source: Photograph © The McGraw-Hill Companies, Inc./Bob Coyle, photographer.

Sandstone

Source: Courtesy of Carla W Montgomery

The Rock Cycle

• Metamorphic Rocks

– Changed form

– Heat, pressure, fluids

– Metamorphism: contact vs regional

Source: Courtesy of Carla W Montgomery

Quartzite

Source: Courtesy of Carla W Montgomery

Figure 2.12D