Minerals, Rocks and Fossils

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Minerals, Rocks and Fossils
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What is a mineral?

• Naturally occurring
• Non-organic
• Characteristic chemical composition
• Distinctive physical properties
• Crystalline structure

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Mineral properties

• Color
• Luster
• Habit (Shape)
• Cleavage Fracture
• Streak
• Hardness
• Other

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Color

• Not mineral specific

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Luster

• How minerals reflect light

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Mineral Habit (Shape)

• Shape a mineral takes if grown unimpeded
• Mineral Java Applet

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Cleavage Fracture

• Cleavage planes of weakness along which minerals
  can break
• Fracture surfaces along which minerals can break

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Cleavage Fracture
Best identified on a fracture surface
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Streak

• The powdered form of a mineral

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Hardness

• Based on Mohs scale of hardness

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Other Properties

• Specific gravity
• Reaction to acid
• Striations
• Magnetism

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Classifying Rocks

• Rocks are classified by how they formed and what
  theyre made of
• There are 3 general classes of rocks
• Igneous Rocksare formed when lava and magma
  crystallize to form solid rock
• Metamorphic Rocksare formed when an existing
  rock is partially melted, squeezed, or both
• Sedimentary Rocksare formed when sediments (sand
  clay, and silt) are compressed and become solid
  rock

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Igneous Rocks
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Metamorphic Rocks
Schist
Gneiss
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Sedimentary Rocks


Shale
Conglomerate

Sandstone

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Fossils
The remains or imprints of living things of the
past found in Sedimentary rocks.
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Fossils provide information about life and
conditions in the past.
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Fossils of Sea Creatures

• Oceans once covered the area
• What part of the ocean

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Fossils of Plants

• Plant fossils can tell us about the ancient
  environment

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Animal Fossils

• Animal fossils can tell us
• About past environments
• What the animal ate
• How they lived