1. Chapter 20: Earth Materials
Table of Contents
Chapter 20: Earth Materials
Section 20.1: Minerals

2. Composition of Earth’s Crust
Minerals 1
Composition of Earth’s Crust
The (A.) The orderly arrangement of a minerals atoms makes it crystalline

3. Minerals 1
Atom Arrangement
Minerals (B1) break along planes that cut across relatively weak chemical bonds is called cleavage. If there are not weak chemical bonds the minerals break with fracture

4. Minerals 1
Atom Arrangement
(B2) Bonds connecting atoms can have different strengths. Scratching occurs as bonds in atoms are broken. Minerals with higher hardness have stronger bonds between atoms.

5. Minerals 1
Hardness

6. Minerals 1
Luster and Streak
(B3) Metallic luster minerals reflect light in a way that a polished metal surface might.
(B3) Nonmetallic minerals do not shine like polished metals.

7. Minerals From Hot Water1
Minerals From Hot Water
Some minerals are produced from (C) hot water solutions rich in dissolved mineral matter.

8. Minerals 1
Minerals from Magma
Molten rock material found inside Earth is called magma.
(C.) As magma cools, atoms slow down and begin to arrange into an orderly structure.

9. Minerals 1
Minerals From Water
(C) When water slowly evaporates, concentrated dissolved mineral may be left behind to form crystal.

10. Mineral Uses (D) Uses of common minerals
Quartz—glass, watches, gems, concrete
Graphite—pencils, lubricants
Halite—food preservative, salt
Calcite—optics, cement

11. Igneous Rocks 2
Nature of Magma
The (A.) minerals in the rock depend on the chemical composition of the magma from which it formed.

12. Types of Magma
(B) Granitic magma: contains quartz, light in color, on continents, Thick and slow moving due to the silica in the quartz.
Andesitic magma: composition between granitic and basaltic.
Basaltic magma: little quartz, more iron, dark color, thin and runny due to little silica. On ocean floor.

13. Texture
The size of the mineral crystals in a rock is called the (C) texture.
coarse: large minerals caused by slow cooling underground.
Fine: small minerals due to fast cooling on the surface.
Glassy: no individual mineral crystals due to instant cooling after a volcanic eruption.

14. Igneous Rocks 2
Effect of Gases
Magma contains small amounts of (CD.) dissolved gases, such as, water vapor and carbon dioxide. They can produce air holes in an extrusive rock after the gases escape.

15. (E) Igneous Rocks 2 Extrusive Intrusive Formed from lava
Formed on the surface
Cools quickly
Fine or glassy texture
Small grains or no grains
EX: rhyolite Pumice
basalt obsidian
scoria
Intrusive
Formed from magma
Formed underground
Cools slowly
Coarse texture
Large mineral grains
EX: granite
gabbro

16. Igneous Rock Composition
Igneous Rocks 2
Igneous Rock Composition

17. Rocks From Surface Materials
Sedimentary Rocks 3
Rocks From Surface Materials
Rocks inside Earth are protected from surface conditions.
(A) Rock exposed at the surface is attacked by the weather.

18. (B) Sedimentary Rock 3 Clastic (Detrital)
Sedimentary Rocks 3
(B) Sedimentary Rock
Clastic (Detrital)
Formed from rock sediments on the surface
Formed by compaction and cementation
EX: Sandstone, shale
conglomerate,
breccia
Chemical
Formed by precipitation of minerals or evaporation of water.
EX: Limestone

19. Organic (Biochemical) Formed from remains of living things Formed by compaction and cementation EX: coal, shell limestone

20. (A) Foliated Has visible layers EX: gneiss slate schist Nonfoliated
Does not have visible layers
EX: marble
quartzite

21. Igneous sedimentary metamorphic Compaction & cementation
Weathering & erosion
Heat & pressure
melting
Weathering & erosion
Weathering & erosion
metamorphic
Heat & pressure
Igneous
melting
melting
Cooling & hardening