A
Tests for hardness and streak help ______minerals.
identify
Some minerals are formed when ________cools.
mangma
When liquid evaporates, atoms of any dissolved minerals stay behind and form ______.
crystals
A mineral is an inorganic ______with a unique crystal structure.
solid
how light is reflected from a mineral
luster
a measure of how easily a mineral can be scratched
hardness
color of a powdered mineral
streak
the tendency of a mineral to break along a smooth, flat surface
cleavage
the tendency of minerals to break with rough or jagged surfaces
fracutre
the distinctive yellow of sulfur
color
One of the softest minerals is
talc
Igneous rocks that form _______the surface are intrusive.
below
The individual bits of minerals, smaller rock fragments, organic matter and glass that make up a rock.
grains
Igneous rocks form from _______ when it cools.
lava and/or magma
The crystals that form in slowly cooled magma produce _______ mineral grains.
large
When lava cools at Earth's surface, ______igneous rocks are formed.
extrusive
Calcite will scratch gypsum. This is an example of the physical characteristics called ________.
hardness
When magma cools deep inside Earth, _______ igneous rocks are formed.
intrusive
The molten material deep inside Earth from which igneous rocks form is called ______.
magma
Metamorphic rocks that show layers of dark minerals alternating with layers of light minerals are classified as __________.
foliated
Sedimentary rocks are changed to sediments by ________.
weathering and erosion
The _________shows how one rock changes into another.
rock cycle
Muscovite mica will peel off in flat sheets. This is an example of the physical characteristic called _______.
cleavage
Foliated rocks are distinguished by ____________.
layers
When does metamorphism occur?
when rocks are subjected to high temperatures and pressure