Identify the Rocks Do Now

Rock Identification For each Rock: IGNEOUS METAMORPHIC SEDIMENTARY Write down the name. Write down whether it is: IGNEOUS METAMORPHIC SEDIMENTARY Copy any clues that you may need to remember these rocks.

Limestone Chemical composition – forms from the precipitation of Calcite (CaCO3) Dissolved by groundwater to form caves, sinkholes, and karst terrain. Located in the Valley and Ridge

Gneiss Has stripes because mineral grains line up into a foliated texture.

Obsidian This rock has no crystalline structure. Actually volcanic glass. Usually black Can be used as a scalpel.

Basalt This is a mafic rock. Dense and usually found at the bottom of the ocean. Forms as lava surfaces and cools quickly.

Sandstone Formed from beach sand or desert sand. May have cross-bedding structures. Clastic composition.

Granite This is an intrusive rock. Coarse-grained Used as countertops or decorative stone in buildings. Quartz, Mica, Feldspar

Conglomerate Clastic texture Coarse-grained Pieces of different rocks compacted and cemented together.

Quartzite Nonfoliated form of sandstone after being changed by heat and pressure.

Shale Clastic composition Made of clay-sized particles. Breaks into thin, flat layers.

Slate Used to be Shale but has changed into a harder rock by heat and pressure. Flat layers of rock. Used for Slate Roofs. Makes a good roofing shingle.

Schist Foliated texture. Sometimes contains garnets due to the depth and pressure at which it forms.

Marble Limestone can change into marble when affected by heat and pressure. Used for flooring, statues, and decorative stone. Nonfoliated.

Pumice This rock is extrusive. Full of air pockets. Very low density. Sometimes floats.