Transcript Rocks: Mineral Mixtures

Rocks: Mineral
Mixtures
th
8
Grade
Section 1:
Understanding Rock
• What exactly is rock?
–A solid mixture of crystals
of one or more minerals,
that range in all sizes from
pebbles to formations that
are thousands of kilometers
long.
The Value of Rock
• Rock is an important natural resource.
• Used by early humans to make tools
such as hammers, spears, knives, and
scrapers.
• Used for centuries to make buildings,
roads, and monuments.
• Certain types of rocks have helped build
ancient and modern civilizations.
• Rock study has helped scientists to
discover the history of life on Earth.
Machu Picchu, Peru 600 A.D.
Ancient Civilization Rock Structure
Fossils
• Help provide information of life forms
that lived thousands of years ago.
The Rock Cycle
• Rocks in the Earth’s crust are
constantly changing shape and
composition.
• The way the rock forms determines
the type of rock that it is.
• The three main types of rocks are:
igneous, sedimentary, and
metamorphic.