Download Rocks

Chapter 5 Section 1
Page 146- 149
A.
When studying a rock sample, geologists classify
rocks by:
1. Color
2. Texture
3. Mineral composition
4. Origin
B. Most rocks are made up of particles of
minerals or other rocks, called grains
C. A rock's texture is the grains’
1. size
2. shape
3. pattern
In identifying rocks, geologists
also use some of the tests that
are used to identify minerals
I hope you remember the 8 ways
geologists identify minerals!
D. There are three major groups of rocks:
1. Igneous rock
2. Sedimentary rock
3. Metamorphic rock

Very Important! Pay Attention!
 Rocks are classified by the way
they are formed!
 Igneous rock forms from the cooling of molten
rock—either magma below the surface or lava at the
surface
 Sedimentary rock forms when particles of other
rocks or the remains of plants and animals are pressed
and cemented together.
 Sedimentary rock forms in layers.
 Metamorphic rock is formed when an existing
rock is changed by heat, pressure, or chemical
reactions.
 Most metamorphic rock forms deep underground.
Gneiss
Schist