MINERALS OF THE EARTH’S CRUST

Earth ScienceChapter 1.1

What is a Mineral?

Objectives:1. Describe the structure of minerals2. Describe the two major groups of minerals

Bellringer:

Compare the piece of pencil lead and the diamond in the photograph provided by your teacher. Both substances are composed of carbon. How can the same element form two substances with such different properties?

Mineral Structure Mineral

Naturally formed, inorganic solid that has a definite crystalline structure

You can tell whether an object is a mineral by asking four questions1. Is it a nonliving material?2. Is it a solid?3. Does it have a crystalline structure?4. Is it formed in nature?

Elements pure substances that cannot be separated or broken

down into simpler substances by chemical means

Atoms and CompoundsMinerals may be either elements or compounds

Compound substance made of atoms of two or more different

elements joined by chemical bonds Native element

Mineral that is composed of only one element○ Examples: Gold and Silver

Native Gold Native antimony

Native silver

CrystalsSolid, geometric forms of minerals produced by a

repeating pattern of atoms that is present through-out the mineral

Shape ○ Determined by the arrangement of the atoms within the

crystalArrangement of atoms

○ determined by the kinds of atoms that make up the mineral

Halite, NaCl

Silvite, KCl Fluorite,

CaCl2

Two Groups of Mineralsbased on their chemical composition

1. Silicate mineralsminerals that contain a combination of silicon,

oxygen, and one or more metals○ Examples : quartz, feldspar, and mica

2. Nonsilicate minerals Minerals that do not contain compounds

of silicon and oxygen Six main classes

1. Native elements One element Copper - Cu, Gold - Au, Silver - Ag

2. Carbonates Combination of carbon and oxygen Cement, building stone, fireworks

3. Halides Form when halogen combine with sodium,

potassium, or calcium Chemical industry and detergents

Fluorite, calcium fluoride

copperCalcite, calcium carbonate

Azurite, copper carbonate

4. Oxides Form when aluminum or iron combine with

oxygen Abrasives, aircraft parts, paint

5. Sulfates Contain sulfur and oxygen, SO4

Cosmetics, toothpaste, cement, and paint

6. Sulfides Contain lead, iron, or nickel combined with

Sulfur. Batteries, medicines, electronic parts

Corundum, aluminum oxide

Zincite, zinc oxide

Gypsum, calcium sulfate

Baryte, barium sulfateGalena, lead sulfidePyrite, Iron sulfide“Fools Gold”