Deck 27: Minerals and Igneous Rocks

Question 1

Generally, the ____ amount of time for a mineral to form, the _____ the crystal size. (Mark all that is true).

A) longer; larger
B) shorter; larger
C) longer; smaller
D) shorter; smaller

Answer 1

A, D

Question 2

In order for a substance to be defined as a mineral, it must exhibit the following characteristics:

A) naturally occurring, inorganic compound
B) definite chemical composition
C) orderly crystalline structure
D) all of the above

Answer 2

D

Question 3

Diamonds and graphite are composed of the exact same element (carbon), but both differ significantly in hardness. Which statement is NOT true with regards to their hardness?

A) graphite atoms are arranged in sheets and are held together by weak bonds
B) diamonds are arranged in a tetrahedral crystalline structure
C) diamonds are held together by very strong bonds
D) color determines the hardness for each mineral

Answer 3

D

Question 4

Rocks are composed primarily of minerals.

Question 5

Imagine working in the field and discovering a mineral that looks like a diamond. Which common mineral could you use to determine whether the mineral was a valuable diamond or a common quartz crystal by performing a scratch test? Refer to Moh's hardness scale (Table 27.1).

A) calcite
B) topaz
C) gypsum
D) apatite

Question 6

Atom is to molecule, as mineral is to _____.

A) electron
B) proton
C) mineral
D) rock

Question 7

The tendency of minerals to break along zones of weakness and producing bright plane surfaces is known as:

A) cleavage
B) fracture
C) hardness
D) luster

Question 8

The most obvious, but most unreliable, property used to identify a mineral is:

A) hardness
B) color
C) luster
D) streak

Question 9

Rocks that form from deposition, compaction, and cementation of sediments are called:

A) sedimentary rocks
B) igneous rocks
C) metamorphic rocks
D) crystals

Question 10

Metamorphic rocks are rocks that have changed by:

A) heat
B) pressure
C) time
D) both (a) and (b)

Question 11

Generally, extrusive rocks are characterized by their _____ appearance.

A) coarse grained
B) light colored
C) fine grained
D) dark colored

Question 12

As the rate of cooling decreases, crystal size ____.

A) decreases
B) increases
C) stays the same
D) increases and then decreases

Question 13

Obsidian:

A) cools slowly and has a glassy appearance
B) cools rapidly and forms one large crystal
C) cools slowly and forms large crystals
D) cools rapidly and has a glassy appearance

Question 14

Another term used to describe a dark-colored igneous rock is:

A) mafic
B) aphanitic
C) felsic
D) granitic

Question 15

Granite and gabbro have:

A) similar coarse grained texture
B) similar mineral composition
C) similar composition but different texture
D) erupted and cooled at the surface

Question 16

Magma that cuts through rock layers, cools, and solidifies forms a:

A) stock
B) sill
C) dike
D) laccolith

Question 17

Laccoliths are:

A) large discordant structures that bulge in a dome-like manner
B) vertical layers that cut through rock layers
C) a massive pluton assimilating surrounding rock structures
D) an intrusive body forming between rock layers pushing overlying rock upwards

Question 18

Separation along planes of rock without any obvious movement along the plane produces a:

A) fracture
B) fault
C) exfoliated surface
D) joint