Download luster

Minerals are natural, nonliving
substances that make up rock.
Rocks can be made up of more
than one mineral.
There are more than 3,000 kinds
of minerals with different
properties. A property is a
characteristic that describes
something.
The four
properties of
minerals are
color, hardness,
luster, and
streak. You can
identify minerals
by their
properties.
COLOR
Minerals can be many different
colors or the same color.
HARDNESS
Hardness refers to a mineral’s
ability to scratch another mineral
or be scratched by another
mineral. Each mineral is
numbered one to ten.
Mohs’ Hardness Scale
LUSTER
Luster refers to the way light
bounces off the surface of a
mineral. Minerals may be
metallic (shiny), dull, glossy, or
pearly in luster.
STREAK
A mineral’s streak is the color of
the powder left behind when it is
scratched on a white tile.
The three main types of rocks are
igneous, sedimentary, and
metamorphic.
Igneous rocks form from melted
rock (magma or lava) cooling and
hardening.
When igneous
rocks cool slowly,
large mineral
grains form. When
they cool more
quickly, there is no
time for large
mineral grains to
form. The rocks
are more smooth.
Sedimentary rocks form from
sediments that are pressed
together. Sediments are tiny pieces
of rock, shells, or bits of plants.
Sediments are deposited by wind
and water (erosion) and over time
pile up on top of older layers of
sediment. When they are pressed
or “cemented” together they form
sedimentary rocks.
Fossils are often found in
sedimentary rock. A fossil is a
trace of something that was once
alive.
Metamorphic rocks are formed
from igneous, sedimentary, or
other metamorphic rock. The high
temperatures and pressures below
the Earth’s surface can change
the properties of rocks, turning
them into metamorphic rocks.
Sedimentary, igneous, and
metamorphic rocks can change
from one type of rock to another
through the rock cycle.