Final Flashcards
When light rays are split into two parts as they enter a crystal it is called?
double refraction
What is the ability of a mineral to resist scratching called?
hardness
How many minerals are referred to as rock forming minerals?
8
Which of the following was NOT a property used to identify minerals in the “Mineral Identification” lab?
Density
Which of the following minerals is a mineral that acts as a magnet?
magnetite
How many kinds of minerals have scientists identified?
about 3000
The easiest way to observe the streak of a mineral is to
rub some mineral against the streak plate
When magma cools quickly, _______ crystals form, and when it cools slowly, ________ crystals form.
small, large
The color of a mineral in powdered form is called the mineral’s
streak
Cleavage is the tendency of a mineral to
split along specific planes, forming flat surfaces.
Which of the following is a question that scientists would ask to determine if a substance is a mineral?
Does the substance occur naturally?
A mineral is a natural solid that usually is
inorganic, with characteristic physical properties.
Density is the ratio of
the mass of a substance to the volume of the substance
The words uneven and splintery describe a mineral’s
fracture
The hardest mineral on the Mohs hardness scale is
diamond
What mineral property involves iron
magnetism
The word waxy, pearly, and dull describe a mineral’s
luster
A _______ is a solid in which the atoms are arranged in repeating patterns.
crystal
Which of the following is NOT one of the four criteria for determining whether or not a substance is a mineral?
it has a shiny surface
A mineral is described as fluorescent when it
it glows under uv light
If a mineral has unrestricted space to grow, what size crystals will develop?
large crystals
What mineral is the softest on Mohs hardness scale
talc
Light that is reflected from a mineral’s surface is called
luster
What mineral fizzes when it comes into contact with hydrochloric acid?
calcite
Color alone is generally
not a reliable clue for identifying a mineral sample.
What kind of streak do metallic minerals generally have?
dark
Which of the following groupings list only minerals?
sulfur, quartz and talc
The common minerals are called
?
What are the two main lusters of minerals that we used in class?
metallic and non metallic
Which of the following is NOT one of the three major types of rocks?
obsidian
Magma forms when rock
melts
Which of the following is NOT a type of sedimentary rock?
volcanic
Most metamorphic rock forms as a result of
regional metamorphism.
One reason that minerals precipitate is because of
evaporation
Which of the following is NOT a type of clastic rock?
fossil
The process by which different minerals melt at different temperatures is called
partial melting.
Sedimentary rock that forms when minerals precipitate from a solution or settle from a suspension is called
chemical sedimentary rock.
The first minerals to melt have the
lowest melting point.
Rock that is formed from magma that is light in color and contains a lot of silica is known as
felsic rock.
How does the cooling process of magma compare with the melting process?
The cooling process is the reverse of the process of partial melting.
Which of the following does NOT change the form of existing rock?
light
What type of sedimentary rock is composed of angular fragments
breccia
The solid part of Earth is made up of material called
rock
Adding fluids to hot rock generally
decreases the melting point of certain minerals in the rock.
What type of sedimentary rock is formed from minerals that were once dissolved in water?
chemical
Magma or igneous rock that is rich in feldspar and silica is
felsic
Which of the following is not a type of metamorphism?
geochemical metamorphism
An example of a nonfoliated rock used as a building or sculpting material is
marble
Which type of rock forms from cooled molten rock?
igneous
Which of the following does NOT change the form of existing rock?
light
Two examples of chemical sedimentary rocks are
gypsum and halite.
The series of changes that describes how geologic forces cause rock to change from one type to another is known as
rock cycle
Sedimentary rock that is made up of rock fragments that become compacted or cemented together is
clastic
Intrusive igneous rocks are characterized by a coarse-grained texture because they contain
large crystals.
The crystallization and removal of different minerals from cooling magma is called
fractional crystallization.
The process in which one type of rock changes into another type of rock because of chemical processes or changes in temperature and pressure is called
metamorphism.
What type of rock texture results when extreme pressure causes minerals in metamorphic rock to realign, or when minerals separate out into dark and light bands?
foliated
As temperature drops, the first minerals to crystallize from magma have
the highest freezing point.
What are four factors that determine whether rock melts?
Heat, pressure, mineral content, and the presence of fluid.
Rock melts when
its temperature rises above the melting point of minerals in the rock.
Which of the following is NOT an igneous texture?
felsic
Light-colored igneous rocks are generally part of the
felsic family.
In regional metamorphism, the change in rocks is the result of
changes in temperature and pressure over a large area.
The idea that states that if sedimentary rock is left undisturbed will remain in horizontal layers is called
original horizontality
Why is radioactive decay used to determine the absolute age of rocks?
Radioactive decay happens at a relatively constant rate.
If the percentage of daughter isotopes present in a radioactive sample is greater than the percentage of parent isotope,
the rock is older.
The half life of U-238 is 4.5 billion years. How many years would 16 g of U-238 take to decay into 0.5g of U-23 and 15.5g of daughter products?
22.5 billion years
Scientists can assume that sedimentary rock layers that are not horizontal have been tilted or deformed by crustal movements after the layers formed by using the
Principal of Original Horizontality
Carbon-14 is an isotope
used to date objects less than 60,000 years old.
Relative age:
is the age of an object in relation to other objects.
Geologists estimate that the earth is about
4.6 byo
In radiometric dating, scientists compare the proportion of a radioactive parent isotope to a stable
daughter isotope.
What is the name of the Scottish scientist who came up with the idea of uniformitarianism?
James Hutton
The principle of uniformitarianism states that
current geologic processes can explain past processes.
The numeric age of an object is called
absolute age.
Which of the following is NOT a criteria for a fossil to be considered an index fossil?
The organisms from which the fossil formed must have lived during a long span of geologic time.
Methods for absolute dating of an object or event include:
studying ice cores
varve count
studying tree rings
Index fossils found in rock layers in different areas of the world indicate that the rock layers
formed during the same period of time.
If an igneous intrusion is observed through a layer of sedimentary rock, what geological law applies?
law of crosscutting relationships
The principle that Earth’s history can be explained by current geologic processes is
uniformitarianism.
