Eas 101 Test 2

Front 1

mineral

Back 1

a naturally occurring solid, formed by geologic processes, that has a crystalline structure and a definable chemical composition, and in general is inorganic

Front 2

biogenic minerals

Back 2

substances that are identical in character to minerals produced by geologic processes, but are the byproduct of living organisms. Biogenic substances that cannot be formed by geologic processes are NOT considered minerals.

Front 3

Crystal Lattice

Back 3

the name for the orderly pattern in which atoms are fixed in a crystalline solid

Front 4

Crystal-

Back 4

a single, continuous piece of a crystalline solid bounded by flat surfaces called Crystal Faces

Front 5

Crystal Faces

Back 5

flat surfaces that grew naturally as the crystal formed.

Front 6

polymoph

Back 6

two different minerals that have the same composition but different crystal structures

Front 7

geode

Back 7

a mineral lined cavity in a rock, which can happen when crystals formed by precipitation from a solution grow from the wall’s container (e.g. a crack or pore in a rock).

Front 8

Luster

Back 8

refers to the way a mineral surface scatters light.

Front 9

streak

Back 9

refers to the color of a powder produced by pulverizing the mineral.

Front 10

Hardness

Back 10

- is a measure of the relative ability of a mineral to resist scratching, and therefore represents the resistance bonds in the crystal structure to being broken.

Front 11

Mohs Hardness Scale

Back 11

scale created by Friedrich Mohs to determine hardness of minerals relative to each other (ex: any mineral with a hardness of 5 can scratch any other mineral with a hardness of 5 or below)

Front 12

Specific Gravity

Back 12

represents the density of a mineral, as specified by the ratio between the weight of a volume of the mineral and the weight of an equal volume of water at 4 degrees Celsius.

Front 13

Crystal Habit

Back 13

refers to the shape (morphology) of a single crystal with well-formed crystal faces, or to the character of an aggregate of many well-formed crystals that grew together as a group.

Front 14

Cleavage

Back 14

the term applied to a mineral that fractures to form distinct planar surfaces with specific orientation in relation to the crystal structure.

Front 15

Conchoidal Fractures

Back 15

are smoothly curving, clamshell-shaped surfaces; they typically form in quartz. Glass, even though it has no crystal structures, can form conchoidal fractures.

Front 16

Silicon-Oxgen Tetrahedron

Back 16

an anionic group made from a silicon atom surrounded by four oxygen atoms that are arranged to form the corners of a tetrahedron.

Front 17

Silicate Minerals

Back 17

the minerals that compose over 95% of the continental crust. Most rocks in the oceanic crust and the earths mantle are also silicate minerals, making it one of the most common minerals on Earth.

Front 18

gem

Back 18

cut and finished stone ready to be used in jewelry.

Front 19

Facet

Back 19

ground and polished surfaces on a gem that are made smooth through use of a faceting machine.

Front 20

solid-state diffusion

Back 20

the movement of atoms or ions through a solid to arrange into a new crystal structure

Front 21

biomineralization

Back 21

physical and biological components of the earth system interface (ex: clams extract ions from water to form mineral shells

Front 22

fumerolic mineralization

Back 22

process hat occurs around volcanic vents or geysers. When gases are emitted in these places, they cool, and emit minerals.

Front 23

Euhedral crystals

Back 23

crystals form as a result of the mineral having unobstructed room to grow

Front 24

Anhedral grains

Back 24

minerals that form when a mineral’s growth is contained by its surroundings and does not have well-formed faces

Front 25

volcano

Back 25

a vent at which melt from inside the earth spews onto the planets surface.

Front 26

Lava

Back 26

melt that has reached the surface.

Front 27

Igneous Rock

Back 27

rock made by the freezing of melt.

Front 28

Magma

Back 28

melt that exists below the surface.

Front 29

Intrusive Igneous Rock

Back 29

rock made by freezing of magma underground.

Front 30

Pyroclasic Debris

Back 30

debris that have been blasted out of a volcano.

Front 31

Geotherm

Back 31

the variation in temperature and depth that can be expressed on a graph by drawing a curving line. Heat increases more slowly with depth.

Front 32

Felsic Magma

Back 32

contains between 66-76% silica. Not very dense, contains minerals such as feldspar and quartz.

Front 33

Intermediate Magma

Back 33

contains 52-66% silica, composition is between felsic and mafic.

Front 34

Mafic Magma

Back 34

contains 45-52% silica, produces rocks containing mafic materials such as the minerals iron and magnesium.

Front 35

Ultra Mafic Magma

Back 35

contains only 38-45% silica. Very dense.

Front 36

Partial Melting

Back 36

the process during which only part of a rock melts to form a magma that then moves away.

Front 37

Assimilation

Back 37

when rocks fall into magma in a magma chamber and melt, or when the walls of the chamber melt.

Front 38

Fractional Crystallization

Back 38

magma changes composition as it cools because formation and sinking of crystals preferentially remove certain atoms from the magma.

Front 39

Bowen’s Reaction Series

Back 39

as new crystals form during crystallization, they preferentially extract certain chemicals from the melt. Thus, the chemical composition of the remaining melt progressively changes as the melt cools. Further, once cooled, crystals continue to react with the melt. The Bowen Reaction Series therefore describes the specific sequence of mineral-producing reactions that take place in a cooling, initially mafic, magma.

Front 40

Dike

Back 40

a vertical tabular intrusion.

Front 41

Sill

Back 41

a horizontal tabular intrusion.

Front 42

Laccolith

Back 42

an intrusion that initially interjects between layers but then domes upwards.

Front 43

Pluton

Back 43

an irregular, blob-shaped, intrusion that ranges in size from tens of meters across to tens of kilometers across.

Front 44

Batholith

Back 44

a collection of plutons that is several hundred kilometers long and up to a hundred kilometers think.

Front 45

Stoping

Back 45

the process during which pluton assimilates wall rocks, and then wall rock breaks off and sink into the magma.

Front 46

Xenolith

Back 46

a stopped block that does not melt entirely but instead becomes surrounded by new igneous rock.

Front 47

Glassy Igneous Rock

Back 47

rocks that are made of a solid mass of glass or of tiny crystals surrounding glass.

Front 48

Crystalline igneous rock

Back 48

rocks that consist of mineral crystals that inter-grow and have an interlocking texture.