Identification of Rocks is by texture and composition Rocks are aggregates of minerals Identification of Rocks is by texture and composition Texture is the size, shape and arrangement of grains Composition is the minerals in the rock.

Grain Size Fine Medium Coarse Glassy

Arrangement - Cemented

Arrangement - Interlocking

Arrangement - Foliated Arrangement - Frothy

04_02.jpg Igneous Rocks – cooling of magma or lava. Intrusive and Extrusive Composition: silicic, mafic, intermediate

Sedimentary Rocks Chemical – precipitated from water – interlocking Clastic – cemented fragments Carbonates – cemented shell fragments Chemical – precipitated from water – interlocking Composition (Minerals): calcite, dolomite, quartz, halite

Regional Metamorphism - Foliation

Marble 06_17.jpg Limestone Contact Metamorphism of Limestone