Chapter 4-1 - The Rock Cycle - Characteristics of the Rock Groups

	A rock is a mixture of minerals, mineraloids, glass, or organic matter.

Igneous- massive crystals throughout; may be light or dark; may be fine or coarse; crystals cannot be separated out.

Sedimentary- stratification (layering); bedding planes; dirty or dull; may be broken into pieces; may have fossils or odor.

Metamorphic- individual crystals are indistinguishable; foliation (parallel bands); planes visible but cannot be separated; very dense