Download Rocks and Minerals - LCS Essentially Science

Rocks and Minerals
•Hold secrets to Earth’s past
•Valuable natural resources
•How do you use rocks and
minerals in your everyday life?
Building Blocks
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Rocks are made of minerals
Minerals are made from elements
Elements are made of atoms
Atoms are made of electrons, protons and
neutrons
Bonds
• Elements react and form bonds
• Either ionic or covalent
• Most common crustal elements are
oxygen and silicon
• Bond covalently into silica tetrahedron
• Tetrahedron can bond to other elements
Minerals
• Naturally occurring inorganic solids of one
or more elements that have a definite
chemical composition with an internal
arrangement of atoms
Classifying minerals
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Crystal form
Cleavage
Hardness
Luster
Streak
Acid test
Rock Types
• Igneous
• Sedimentary
• Metamorphic
Igneous Rocks
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Form from cooling magma
Cooling can be fast or slow
Slow makes big crystals = plutonic
Fast makes small crystals = volcanic
Amount of silica matters largely a
function of continental input
• Basalt – Andesite - Rhyolite
Sedimentary Rocks
• Clastic from weathering of rocks
– Grain size
– Transport
• Chemical from precipitation
• Biogenic from living organisms
Metamorphic
• Composition or texture of a rock changes
due to changing temperature, pressure or
chemical reaction
• Temperature needed 200-1100˚C
• Contact versus regional
• Foliation