Rocks

Compare the 2 samples: Similarities Differences Compare the 3 samples

Rocks? What are minerals?? Crystal Shape Naturally occurring Consistent Chemical Composition Inorganic Solid

Rocks Solid Made from mixtures of: 3 groups Minerals or Minerals + parts of things Dead things Man-made objects 3 groups Distinguished by how they are made Can change between types over time

Rock Forming Minerals Of the 4,000 minerals available….only 20 form rocks

Identifying Rocks Color: Not too helpful Light-granitic Dark-basaltic

Rock Texture Texture is key Based on Grain appearance Pieces of minerals that make up the rock

Rock Texture Grain Size Grain Shape Grain Pattern

Texture Practice

Classification Review Top of Page _______

3 Types of Rock

3 Types of Rock Igneous: Sedimentary: Metamorphic: Melted rock Broken grains of many rocks joined together Metamorphic: Changed from Heat & Pressure

Igneous Rocks Intrusive Extrusive Very 1st rock group on Earth 2 Groups: Based on Cooling Rates Intrusive Extrusive Magma cools slowly Have large grains Lava cools quickly Have small grains

Extrusive or Intrusive Pumice Basalt Granite Obsidian Tuff

Uses of Igneous Rocks Tools Building Materials

Uses of Igneous Rocks Scrubbing/cleaning Gravel

So Far… Rocks Igneous Sedimentary Metamorphic Extrusive Intrusive

Igneous Sediments Sedimentary