Chapter 3 Earth Materials: Minerals And Rocks

Question 1

What are minerals?

Answer 1

Minerals are the building blocks of rocks

Question 2

What is a Mineral?

Answer 2

A naturally occurring, solid crystalline substance, usually inorganic, with a specific chemical composition.

Question 3

What kind of chemical bonds do we find in nature?

Answer 3

Ionic bonds: electrostatic attraction between ions of opposite charge

Covalent bonds: sharing of electrons

Metallic bonds: freely mobile electron sharing dispersed among cations

Question 4

How do minerals form?

Answer 4

By the process of crystallization where atoms in the liquid or gaseous come together in the proper chemical proportions and proper special arrangement to form a solid substance.

Question 5

What are crystals?

Answer 5

Orderly three-dimensional arrays of atoms in which the basic arrangement is repeated in all directions

Question 6

What is a grain?

Answer 6

Solid mass of crystalline particles

Question 7

How do minerals form?

Answer 7

By lowering the temperature of a liquid below its freezing point example ice.

When liquids evaporate from solution forming a precipitate example halite.

Under high temperatures and pressures example diamond.

Question 8

Name the eight classes of rock forming minerals.

Answer 8

Silicates
Carbonates
Oxides
Sulfides
Sulfates
Native elements
Hydroxides
Halides

Question 9

What is a silicate?

Answer 9

The most abundant class of minerals in Earth’s crust, composed of oxygen and silicon-the two most abundant elements in the crust- mostly in combination with cations of other elements. Example Olivine (Mg,Fe)2SiO4

Question 10

Carbonates are minerals composed of c_____ and o______- in the form of the carbonate anion- in the combination with c_____ and m_______.

Answer 10

Carbon
Oxygen
Calcium
Magnesium
Example Calcite CaCO3

Question 11

What is an Oxide?

Answer 11

Compounds of the oxygen anion(O2-) and metallic cations; an example is the mineral hematite(iron oxide, Fe2O3)

Question 12

What is a sulfide?

Answer 12

Compounds composed of the sulfide anion (S2-)and metallic cations an example is pyrite(iron sulfide, FeS2)

Question 13

What are sulfates?

Answer 13

Compounds composed of the sulfate anion (SO42-)and metallic cations an example is anhydrite(calcium sulfate, CaSO4)

Question 14

What are the physical properties of minerals?

Answer 14

Hardness
Cleavage
Fracture
Luster
Color
Density
Crystal habit

Question 15

What is hardness and Mohs scale of hardness?

Answer 15

The ease at which a mineral can be scratched. A scale based on the ability of one mineral to scratch another.

Question 16

Describe Mohs scales of hardness.

Answer 16

Mineral Scale number Common object
Talc 1
Gypsum 2 Fingernail
Calcite 3 Copper coin
Fluorite 4
Apatite. 5 Knife blade
Orthoclase. 6 Window glass
Quartz. 7 Steel file
Topaz 8
Corundum 9
Diamond 10

Question 17

What is cleavage?

Answer 17

Cleavage is the tendency of a crystal to split along planar surfaces also used to describe the geometric pattern produced by such a breakage.

Question 18

What is fracture?

Answer 18

Tendency of a crystal to break along irregular surfaces other than cleavage planes.

Question 19

What is luster?

Answer 19

The way the surface of a mineral reflects light.

Question 20

What are rocks?

Answer 20

A naturally occurring solid aggregate of minerals or in some cases, nonmineral solid matter.

Question 21

What are igneous rocks?

Answer 21

Rocks formed by the solidification of molten rock(magma or lava), such as basalt and granite

Question 22

What are sedimentary rocks?

Answer 22

Rocks formed as the burial products of layers of sediments such as sand, mud, or the calcium carbonate shells of marine organisms.

Question 23

What are metamorphic rocks?

Answer 23

Rocks formed by the transformation of pre-existing solid rock under the influence of high temperatures and pressure.

Question 24

What is the difference between an intrusive and an extrusive igneous rock?

Answer 24

Intrusive igneous rocks crystallize when magma intrudes into unmelted rock masses deep in earths crust forming large crystals such as granite.
Extrusive igneous rocks form when lava cools rapidly at Earth’s surface having a glassy or fine grained texture such as basalt.

Question 25

Name a few common minerals of igneous rocks.

Answer 25

Quartz, feldspars, micas, pyroxenes, amphiboles and olivines.

Question 26

How are sediments deposited?

Answer 26

Siliclastic sediments laid down by running water, wind and ice.

Chemical and biological sediments are formed by precipitation.

Question 27

What is the process that converts sediment to solid rock?

Answer 27

Lithification which occurs via compaction(particles squeezed together by weight of overlying sediments) and cementation(minerals precipitate around deposited particles and bind them together.

Question 28

Sediments and sedimentary rocks are characterized by?

Answer 28

By bedding, the formation of parallel layers of sediment as particles are deposited.

Question 29

Name a few common minerals of sedimentary rocks.

Answer 29

Siliclastic sedimentary rocks are Quartz, feldspar, and clay minerals.
Chemical and biological minerals are calcite, dolomite, gypsum and halite.

Question 30

What types of metamorphism do we get?

Answer 30

Regional and contact metamorphism

Question 31

What are some common minerals of metamorphic rocks?

Answer 31

Silicates such as quartz, feldspars, micas, pyroxenes, amphiboles,kyanite, staurolite, and garnets.

Question 32

What is the rock cycle?

Answer 32

Interactions between the plate tectonic and climate systems

Question 33

What is an ore?

Answer 33

A rich deposit of a mineral from which valuable metals can be recovered profitably

Question 34

What is grade and mass in geological terms?

Answer 34

Grade refers to the concentration of ore minerals within economically valueless parent rock.
Mass refers to the amount of ore that could potentially be extracted from the deposit.

Question 35

What are hydrothermal deposits?

Answer 35

When circulating groundwater or seawater comes into contact with a magmatic intrusion, reacts with it, and carries of significant quantities of elements and ions released by the reaction which then Interact to form ore minerals.