KYTL+5.1

toc

Vocabulary

 * Texture**- the look and feel of the rock's texture
 * Grains**- particles of minerals or other rocks that make up a rock
 * Igneous rock-** forms from the cooling of magma or lava
 * Sedimentary rock-** forms from particles of other rocks or the remains of plants or animals when they are pressed and cemented
 * Metamorphic rock-** an existing rock is changed by heat, pressure, or chemical reactions

How Geologists Classify Rocks

 * rocks important for building
 * mountains, hills, valleys, beaches, ocean floor, all made of rock
 * geologists look at the rock's color/texture to find out its mineral composition

Texture

 * smooth, glassy, rough, or chalky
 * a rock's grains gives its texture
 * terms based on size, shape, pattern
 * Grain Size
 * large, easy to see (coarse grained)
 * small, seen through microscope (fine-grained)
 * Grain Shape
 * some looks like:
 * fine sand
 * small seeds
 * exploding stars
 * some are:
 * jagged
 * rough
 * fine
 * smooth
 * Grain Pattern
 * some lies in:
 * flat layers (__)
 * wavy, swirling patterns (~)
 * multicolored beads (.........)
 * No Visible Grain
 * not all rocks have grains
 * none because they cool very fast when they form
 * smooth, shiny, glassy

Mineral Composition

 * geologist can observe shape/size
 * must cut rock very thin to let light shine through crystals
 * test rock's surface with acid tells whether rock's minerals include compounds or carobnates
 * testing with magnet tells elements are iron or nickel

Origin

 * igneous rock
 * forms by the cooling of magma or lava
 * sedimentary rock
 * forms by the process of pressing and cementing sediments
 * metamorphic rock
 * forms by heat and pressure of any other rocks