Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

6-Understanding Planet Earth > Chapter 3: Minerals Slide Set 9 > Flashcards

Chapter 3: Minerals Slide Set 9 Flashcards

1
Q

What is the geologist’s definition of a mineral?

A

A naturally occurring solid, formed by geologic processes, that has a crystalline structure and definable chemical composition

  • Naturally occurring
  • Formed geologically
  • Solid
  • Crystalline structure
  • Definite chemical composition
  • Inorganic (few exceptions)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How are minerals created?

A
  • true mineral is created by natural processes.
  • Humans can recreate natural processes to make
    minerals.
  • These are called synthetic minerals.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the geologic processes that form minerals?

A
  • Freezing from a melt
  • Precipitation from a dissolved state in water
  • Chemical reactions at high pressures and temperatures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Living organisms can create minerals. What are those called? Give examples

A

Called biogenic minerals to emphasize this special origin

  • Vertebrate bones (apatite)
  • Oyster, mussel, and clam shells (aragonite)
  • Other skeletal types
  • Our own tooth enamel (apatite)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the state of matter of minerals?

A

They are solid.

  • A state of matter that can maintain its shape indefinitely
  • Minerals are solids, not liquids or gases.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

True/False

Minerals can be solid, liquid and gas

A

False

only solids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the structure of minerals?

A

They have a crystalline structure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Atoms in a mineral are arranged in a specific order. This atomic pattern is called a _______

A

crystal lattice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

A solid with disordered atoms is called a _____.

A

glass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

True/False

Glasses are minerals

A

False

Lacking crystalline structure, glasses are not minerals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

True/False

Minerals can be defined by a chemical formula.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Give examples for simple and complex minerals

A

Simple

  • Ice—H2O
  • Calcite—CaCO3
  • Quartz—SiO2

Complex

  • Biotite—K(Mg,Fe)3(AlSi3O10)(OH)2
  • Hornblende—Ca2(Fe2+,Mg)(Al,Fe3+)(Si7Al)O22(OH,F)2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Can minerals be organic? What elements can they contain? Explain

A 
They are mostly inorganic. 
- Organic compounds 
- Contain carbon–hydrogen bonds 
- Other elements may be present. (Oxygen Nitrogen 
   Sulfur)
- Common products of living organisms 
- Most minerals are NOT organic.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is studying minerals important?

A
  • Minerals are the building blocks of the planet.
  • Minerals make up all of the rocks and sediments on
    Earth.
  • Understanding Earth requires understanding minerals.
  • Minerals are important to humans.
  • Industrial minerals—raw materials for manufacturing
  • Ore minerals—sources of valuable metals
  • Gem minerals—attract human passions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a crystal?

A
  • A single, continuous piece of crystalline solid
  • Typically bounded by flat surfaces (crystal faces)
  • Crystal faces grow naturally as the mineral forms.
  • The same mineral has the same crystal faces.
  • Adjacent faces occur at the same angle to one another.
  • Faces and angles reflect crystalline structure.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is an X-ray diffraction?

A

X-ray beam splits into numerous smaller beams. Interference of waves of different beams produces a diffraction pattern on a screen or film. The pattern indicates the spacing and arrangement of atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Physical properties of a crystal (hardness, shape) depend upon:

A
  • Identity of atoms
  • Arrangement of atoms.
  • Nature of atomic bonds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the structure of a diamond like?

A

In diamonds, each atom bonds to four neighbors arranged in the form of a tetrahedron. The bonds between the carbon atoms are covalent, meaning that they share electrons, i.e., their electron clouds overlap and, as a result, the bonds are very strong. … Hardest mineral known to man.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which one is a stronger bond? Covalent or Ionic?

A

Covalent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the structure of a graphite like?

A

Covalent bonding of 3 carbon atoms within each sheet within the sheets carbon atoms share their electrons with three other carbon atoms through covalent bonding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where are diamonds found?

A

Diamonds originate under extremely high pressure.

  • ~150 km deep—in the upper mantle
  • Pure carbon is compressed into the diamond structure.
  • Rifting causes deep-mantle rock to move upward.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How do mineral crystals form? What are the possible processes? Give example

A
  • Mineral crystals form when a melt solidifies. Quick cooling results in tiny crystals; slow cooling creates large crystals.
  • New crystals can form from an aqueous solution when dissolved solids become saturated.
    A common way for this to happen is by evaporation of water.
  • Mineral crystals can sometimes precipitate directly from a gas.
  • As rocks are buried to great depths, new crystals form.
  • Biomineralization forms new crystals. (teeth)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How are minerals formed?

A
  • Outward crystal growth fills available space.

- Resulting crystal shape is governed by surroundings.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The open space is where the ____ faces grow

A

good crystal faces grow

25
Q

The confined space is where there is _____ faces

A

no crystal faces

26
Q

Mineral growth is often restricted by _______.

A

lack of space

27
Q

What does anhedral mineral mean?

A

grown in tight space, no crystal faces

28
Q

What does euhedral mineral mean?

A

grown in an open cavity, good crystal faces

29
Q

Which one is more common anhedral or euhedral?

A

Anhedral crystals are much more prevalent.

30
Q

Euhedral crystals grow into the open space in a ______

A

geode

31
Q

Minerals can be destroyed by:

A
  • Melting—heat breaks the bonds holding atoms together
  • Dissolving—solvents (mostly water) break atomic bonds
  • Chemical reaction—reactive materials break bonds
32
Q

When we say that a material is crystalline we mean that internally . . .

A. atoms are distributed in an orderly arrangement.
B. atoms and/or clusters of atoms are arranged randomly. C. atoms are arranged strictly in microscopic cubes.
D. the material occurs only in crystals with nicely formed
crystal faces.

A

D

33
Q

The chemical formula of quartz is SiO2. This means that if you analyze a piece of quartz, you will find that . . .

A. the piece contains equal parts of sodium and chlorine.
B. the piece contains one silicon atom for every two
oxygen atoms.
C. the piece contains a random mixture of silicon and
oxygen atoms.
D. the piece contains a great variety of different elements.

A

B

34
Q

What are the common physical properties of minerals?

A
  • Color
  • Streak
  • Luster
  • Hardness
  • Specific gravity
  • Crystal habit
  • Fracture or cleavage
35
Q

How is the color of a mineral analyzed and classified?

A
  • The part of visible light that is not absorbed by a mineral
  • Diagnostic for some minerals
  • Malachite is a distinctive green.
  • Some minerals exhibit a broad color range.
  • Quartz (clear, white, yellow, pink, purple, gray, etc.)
  • Color varieties often reflect trace impurities.
36
Q

How is the color interpreted if a mineral is lets say green?

A

A mineral absorbs certain colors/wavelengths, so the color you see when looking at it is the wavelength it does not absorb.
So green is the color that the mineral does not absorb

37
Q

What is the streak of a mineral? How is it interpreted?

A
  • Color of a powder produced by crushing a mineral
  • Obtained by scraping a mineral on unglazed porcelain
  • Streak color is less variable than crystal color.
38
Q

What is the luster of a mineral? How is it interpreted?

A

The way a mineral surface scatters light

39
Q

What are the subdivisions of luster?

A

Metallic—looks like a metal

Nonmetallic

  • Silky
  • Glassy
  • Satiny
  • Resinous
  • Pearly
  • Earthy
40
Q

What is the hardness of a mineral? How is it interpreted?

A
  • Scratching resistance of a mineral
  • Derives from the strength of atomic bonds
  • Hardness compared to the Mohs scale for hardness. (graphite lowest, diamond highest)
41
Q

What is the specific gravity of a mineral? How is it interpreted? Give examples

A
  • Represents the density of a mineral
  • Mineral weight over the weight of an equal water volume
  • Specific gravity is heft—how heavy it feels.
  • Galena—heavy (SG 7.60)
  • Quartz—light (SG 2.65)
  • Galena feels heavier than quartz.
42
Q

What is the crystal habit of a mineral? How is it interpreted?

A
  • single crystal with well-formed faces, or
  • An aggregate of many well-formed crystals
  • Arrangement of faces reflects internal atomic structure
  • Records variation in directional growth rates
43
Q

What are the possible variations in directional growth rates? Explain each

A
  • Blocky or equant—equal growth rate in three dimensions
  • Bladed—shaped like a knife blade
  • Needle-like—rapid growth in one dimension, slow in
    others
44
Q

What is the habit?

A

The habit is the shape of a single crystal with well-formed (euhedral) crystal faces, a macroscopic reflection of the internal arrangement of atoms in the crystal

45
Q

What is a cleavage?

A
  • Cleavage is the tendency for a mineral to break along lattice planes with weaker atomic bonds
  • Cleavage creates flat, shiny (reflective) surfaces that may occur in steps.
  • Cleavage can be distinguished from crystal faces because it is throughgoing; faces are on external crystal surfaces only.
46
Q

What are the possible directions of a cleavage?

A
  • One direction
  • Two directions at 90º
  • Two directions NOT at 90º
  • Three directions at 90
  • Three directions NOT at 90º
47
Q

Glass breaks with ______ fracture

A

conchoidal fracture

48
Q

Can minerals that have no lattice planes cleave? Explain

A

Minerals that have no lattice planes of weakness— bonds equally strong in all directions—will fracture instead of cleave

49
Q

What are Special Physical Properties that minerals can have?

A
  • Effervescence—reactivity with acid (e.g., Calcite)
  • Magnetism—magnetic attraction (e.g., Magnetite)
  • Taste - halite tastes salty
  • Smell - sulfur smells like rotten eggs
  • Feel—tactile response
  • Elasticity—response to bending
  • Diaphaneity—relative transparency
  • Piezoelectricity—electric charge when squeezed
  • Pyroelectricity—electric charge when heated
  • Refractive Index—degree of bending light
  • Malleability—ability to be pounded into thin sheets
  • Ductility—ability to be drawn into thin wires
  • Sectility—ability to be shaved with a knife
50
Q

What statement about the specific gravity of minerals is correct?

A. If a mineral has a specific gravity of 2, then a cubic
centimeter of the mineral weighs twice as much as a
cubic centimeter of water.
B. Galena (lead ore; PbS) has a smaller specific gravity
than halite (table salt; NaCl).
C. The specific gravity is a measure of how fast an object
will fall a distance of 1 m, in a vacuum.
D. The specific gravity of a particular mineral specimen
depends on the size of the specimen.

A

A

51
Q

If a sample has good cleavage in three directions, and each cleavage direction is at right angles to the other two, then . . .

A. the crystal can be peeled apart into thin sheets.
B. the crystal grows to form cube-shaped crystals.
C. if struck with a hammer, a smooth fracture shaped like a clam shell forms.
D. when crystals break, little cube-shaped or brick-shaped fragments form.

A

B

52
Q

Which of the following processes does NOT lead to the formation of a mineral or minerals?

A. Precipitation from an aqueous solution.
B. Instantaneous freezing of molten rock.
C. Slow cooling of molten rock.
D. Precipitation from concentrated gases.
E. Slow diffusion through a solid.

A

A

53
Q

Silicate minerals dominate _______

A

crust and mantle.

54
Q

True/False

In decreasing order of silicon content:
• Felsic (or silicic) 
• Mafic 
• Ultramafic 
• Intermediate
A

False

  • Felsic (or silicic)
  • Intermediate
  • Mafic
  • Ultramafic
55
Q

The SiO44- anionic unit: ________

A

the silicon-oxygen tetrahedron

56
Q

What is the chemical structure of Silicate Minerals

A
  • Four O atoms are bonded to a central Si atom.
  • Define the corners of a four-sided geometric figure
  • The silica tetrahedron is the building block of silicates.
57
Q

Silicate minerals are divided into several classes based on _______

A

how the silica tetrahedra are arranged

58
Q

How are gems cut and shaped for jewelry?

A
  • Facets are ground onto a gem by a lapidary machine.
  • Faceting a gemstone takes a lot of time and effort.
  • Facets are not natural crystal faces.

6-Understanding Planet Earth (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions