Earth’s Rocks

What are rocks?

• Rock – any naturally formed solid in the crust made up of 1 or more minerals

• May have a mixture of properties• Identification– Name the minerals it contains– Color– Density– Texture – based on how they were formed

Igneous Rocks

• Form when melted rock material cools and hardens

• Lava can also cool to form igneous rocks• Used in monuments• Obsidian – solid piece of volcanic glass• Ex. Obsidian, basalt, granite, gabbro

Uses for Igneous Rock

Gravestones

Buildings

Countertops

Tools

Sedimentary Rocks

• Made of small bits of matter joined together– Weathered rocks, shells, remains of living things

• Formed when sediment is compacted or cemented together

• Ex. Shale, siltstone, sandstone, conglomerate, limestone, conquina, bituminous (coal)

Uses for Sedimentary Rock

• Buildings• Monuments• Park Benches• Cement and concrete• Contain fossils or remains of living things of

the past• Almost all fossils are found in sedimentary rock• Energy

Metamorphic Rocks

• A rock formed under heat and pressure from another kind of rock

• The original rock stays solid• They have new useful properties• Slate is used in roofing shingles• Marble for countertops, floors, and statues• Anthracite is a form of hard coal

Uses for Metamorphic Rock

Buildings

Countertops

Roofing shingles

Energy