The solid portion of the Earth's crust, the lithosphere, is composed of naturally occurring materials made up of one or more minerals, called rock. All rocks are composed of minerals.

The image below, taken from the Earth Science Reference Tables, shows how different rock types form from one another.

Minerals
Minerals are the building blocks for all rocks. Minerals are naturally occurring, inorganic, crystalline, solid materials with definite chemical composition, molecular structure, and certain physical properties. Of the more than 2000 minerals on Earth, about a dozen of them make up about 90% of the Earth's crust.

Identifying Rocks and Minerals
Many students have trouble with the identification of rocks and minerals. If you happen to be one of those students please take your Earth Science reference tables out and carefully read over the sections on rocks and minerals. Pages 6, 7, and 16 in the Earth Science Reference Tables are where one will find the necessary information to complete proper rock and mineral identification. For more on rocks and minerals and how to properly identify each refer to the links in the upper left-hand corner of this page. Then go to the multiple-choice questions and your textbook for further practice.

This page and the links at the left are designed to aid students in reviewing the following topics which will appear on the New York State Earth Science Regents Examination. In addition, students may test their knowledge of the material presented here by accessing multiple-choice questions from past Regents Exams.