© 2009 Allan Ludman and Stephen Marshak
MINERALS, ROCKS, AND THE ROCK CYCLE
To understand how relationships among grains differ in igneous, sedimentary, and
metamorphic rocks, because of the way in which the rocks form.
To use textures, and mineral identification to determine if a rock is igneous, sedimentary, or
An assortment of igneous, sedimentary, and metamorphic rocks
• Supplies to make artificial igneous, sedimentary, and metamorphic rocks
• A magnifying glass or hand lens.
• Mineral testing supplies
A rock is an aggregate of mineral grains, fragments of previously existing rock, or
a mass of natural glass. Rocks can form in a variety of ways—some by freezing of a melt,
others by cementing loose grains together, others by precipitation from water solutions,
and still others from changes that happen in response to temperature and pressure
Geologists can identify rocks, and interpret aspects of Earth's history, by
studying two principal characteristics of rocks:
(meaning, the identity
of minerals or glass that make up a rock) and
(meaning, the dimensions and
shape of grains, and the way in which grains are arranged, oriented, and held together).
On our dynamic planet, rocks don’t survive forever—nature recycles materials, using
those in one rock to form new rocks through a series of steps called the rock cycle.
In this Chapter, we first introduce the three basic classes of rocks.
Then we learn
how to observe the characteristics of rocks and how to use these characteristics to classify
Then, you will make “rocks” in the classroom and see how different processes
produce different textures. By combining your mineral identification skills and