Quarter 2 Quiz 1

Question 1

3 ways to melt rock

Answer 1

Adding heat - Increase temperature, add enough heat and you melt rock
Reducing pressure - also called ‘decompression melting’, this occurs when rock is under lots of pressure and that pressure is suddenly released
Adding water - adding water to rock weakens bonds and lowers the melting point by a bit…water acts as a ‘network modifier’

Question 2

Temperature and viscosity of different types of Magma (mafic and felsic)

Answer 2

Felsic magma is more viscous, felsic magma is less hot because it forms shallower than mafic magma
Mafic magma is less viscous, mafic magma is hotter because it forms deeper than felsic magma, in the upper mantle

Question 3

Magmatic differentiation

Answer 3

Rocks of varying composition can arise from a uniform parent magma and ice versa
Process is a result of the fact that minerals have different crystallization (melting) temperatures
Once partial melt forms, it can migrate upwards, leaving the solidified minerals behind (precipitate)
Migrating partial melt can pool in magma chamber, and then eventually erupt
As the temperature of the magma changes, it can form different rocks

Question 4

Intrusive

Answer 4

Rocks that are formed when magma cools slowly into rock below the surface, allowing larger crystals to form (more coarse texture)
Coarse-grained rock is called a phanerite.

Question 5

Extrusive

Answer 5

Rocks that are formed when lava cools rapidly into rock above the surface, allowing insufficient time for larger crystals to form (finer texture)
Fine-grained igneous rock is called an aphanite

Question 6

Extrusive - Glassy

Answer 6

Atoms lack time to organize themselves into minerals
A mineraloid forms instead (mineral-like solid that lacks either a crystal structure or a definite composition or both)
less time than normal extrusive rocks

Question 7

magma vs. lava

Answer 7

magma when below ground, lava when above ground

Question 8

Vesicular rocks

Answer 8

Rocks with air pockets (holes) are known as ‘vesicular’, occurs when gas is trapped in the magma, always extrusive

Question 9

Basaltic magma

Answer 9

has low silica content and low viscosity, meaning it flows quickly

Question 10

Rhyolitic magma

Answer 10

high in potassium and sodium, but low in iron, magnesium, and calcium

Question 11

What is an igneous rock

Answer 11

Rocks that form when rock is melted and re-hardens
A rock must be melted and recrystallized to produce an igneous rock

Question 12

Rock cycle (in basic terms)

Answer 12

The rock cycle describes the gradual ongoing process by which rocks are changing
Rocks change between being igneous, metamorphic, and sedimentary

Question 13

Mineral definition

Answer 13

SINAC
Solid, Inorganic (minerals are not produced by organic processes, not leaves, etc.), Naturally occurring, fixed Atomic Arrangement (crystal lattice), fixed Chemical Composition (formula)

Question 14

Mineral properties are mostly determined by

Answer 14

The internal arrangement of atoms in the mineral

Question 15

Chemical composition - ion substitution

Answer 15

Not quite all minerals have a fixed chemical composition, sometimes atoms with similar atomic radii can substitute out for one another, called ion substitution
Internal structure > chemical composition

Question 16

Crystalline structure

Answer 16

Minerals are the result of atoms joining together through electrical bonds to produce a definite internal structure
It is the nature of the atoms and the strength of the chemical bonds that determine many of the minerals’ physical and chemical properties

Question 17

Mineral resources (ores, mining, etc.)

Answer 17

A number of minerals are valuable to society, either by themselves or by extracting important metals
Ex. gems and precious metals, metals used in electronics and industry, construction, minerals in soil
Metal sulfide ores(others: tin, nickel, aluminum)

Question 18

Ore def and info

Answer 18

A naturally occurring solid material from which a metal or valuable material can be profitably extracted
Mined from underground (tunnels and shafts), surface (open pits or mountain top removal), or placer (riverbank gravels) deposits

Question 19

Major groups of minerals

Answer 19

Silicates, oxides, sulfides, and native elements

Question 20

Silicates

Answer 20

Any mineral with silica and oxygen, most common minerals, ex. quartz, mica, feldspar
Most common minerals

Question 21

Oxides

Answer 21

A metal with an oxygen, ex. Hematite, Sapphire

Question 22

Sulfides

Answer 22

Any metal bonded to a sulfur, ex. pyrite, galena

Question 23

Native elements

Answer 23

things that exist on their own, ex. Gold, silver, sulfur

Question 24

Polymorphism

Answer 24

2 minerals with the same composition can be very different due to their structure
describes how two minerals can have the same chemical composition and be considered different minerals

Question 25

why do we care about minerals?

Answer 25

Everything we use on Earth comes from Earth
Minerals are an extremely important economic and technological resource for humanity

Question 26

Mineral ID (what traits are the most reliable and the ESRT)

Answer 26

Physical properties - color, luster, streak, hardness, cleavage or fracture, density, magnetic, reaction with HCI

Question 27

Streak

Answer 27

Streak - the color of the mineral in powdered form

Question 28

Fracture/cleavage

Answer 28

Cleavage is the tendency of a mineral to split along one or more smooth, flat surfaces. If a mineral does not display cleavage, it is fracture, and breaks unevenly

Question 29

Luster

Answer 29

Either metallic or nonmetallic

Question 30

Hardness

Answer 30

The mineral’s resistance to being scratched/ability to scratch

Question 31

Rocks vs. minerals

Answer 31

Both are solid, both are naturally occurring
Rocks
Solid mixtures of minerals
Might be organic or have organic components
Minerals
Can be expressed by chemical formula
Has definite crystal structure

Question 32

Hardness of glass
hardness of fingernail

Answer 32

Hardness of glass is 5.5
hardness of fingernail is 2.5

Question 33

about how many mineral ‘species; have been discovered?

Answer 33

About 6000

Question 34

Aphanite

Answer 34

extrusive rocks

Question 35

Phanerite

Answer 35

intrusive rocks