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Classifying Rocks Section 4-1. 7 th grade Science. Classifying Rocks. When studying rocks, scientists observe the rock’s mineral composition, color, and texture. Classifying Rocks. Rock Forming Minerals 20 of the minerals that make up a majority of the earths rocks. Classifying Rocks.
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Classifying RocksSection 4-1 7th grade Science
Classifying Rocks • When studying rocks, scientists observe the rock’s mineral composition, color, and texture
Classifying Rocks • Rock Forming Minerals 20 of the minerals that make up a majority of the earths rocks
Classifying Rocks • Granite a light colored rock with a high silica content • Basalt a dark colored rock with a low silica content
Classifying Rocks-Texture • Grains particles in rocks that give rock its texture • Grain size- fine or coarse • Grain shape- round or jagged • Grain pattern- Banded or nonbanded
Classifying Rocks- How rocks Form • There are 3 major groups of rocks
Classifying Rocks- How rocks Form • Igneous Rock made from cooling Magma or Lava
Classifying Rocks- How rocks Form • Sedimentary Rock Forms when particals of other rocks and/or remains of plants and animals are pressed and cemented together • Forms layers
Classifying Rocks- How rocks Form • Metamorphic rock formed or changed by heat and pressure or chemical reactions. Most forms deep underground