Rock Cycle and Types of Rocks

Terms to Know Rock: a mixture of naturally occurring minerals Mineral: any naturally occurring inorganic substance Crystal: many minerals form regular-shaped solids with flat surfaces Metal: a solid material that is typically hard, shiny, malleable, and ductile, with good electrical and thermal conductivity (e.g., iron, gold, silver, copper, and aluminum, and alloys such as brass and steel).

Igneous Rocks Igneous Rock is formed when magma cools and hardens. Magma that erupts onto the surface is called lava. Granite Basalt Pumice Gabbro Obsidian

Crystals in Igneous Rocks When magma cools slowly underground the crystals are large enough to see. When it cools quickly on the surface, the crystals are very small and you would need a magnifier or a microscope to see them. Sometimes, when the magma cools very quickly, it forms a kind of black glass that you cannot see through.

Sedimentary Rocks Sedimentary Rock forms from particles, called sediment, that are worn off other rocks. The sediment gets turned into rock by being buried and compacted by pressure from the weight above it. Conglomerate Sandstone Shale Limestone

The sediments that form into sedimentary rocks are sand, silt, and clay. Sand has the largest particles while clay has the smallest. These rocks often contain fossils.

Metamorphic Rocks Metamorphic Rock is rock that has been transformed by great heat or pressure. It is buried very deep in the earth's crust and sometimes happens when mountains are being made or two plates are pushing against each other. Gneiss Schist Slate Marble

Weathering, Erosion, Deposition Rock Cycle http://www.learner.org/interactives/rockcycle/rockdiagram/ Magma Igneous Rocks Sedimentary Rocks Metamorphic Rocks Melting Cools and hardens Weathering, Erosion, Deposition Heat and pressure

Gemstones Rare, beautiful minerals, usually colourful and polished until they are clear and shiny

Things That Look Like Rocks But Aren’t Beach Glass: bits of glass smoothed down by water Brick Pebble: a piece of man- made brick smoothed down Petrified Wood: a fossil that forms when plants are buried by sediment and protected from decay by oxygen and organisms. Then, groundwater rich in dissolved solids flows through the sediment replacing the original plant material with different minerals.

Can you identify the rocks? http://www.minsocam.org/msa/collectors_corner/id/roc k_key.htm#gneiss