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Rocks: Mineral
Mixtures
8 Grade
th
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.