If you are just beginning rock collecting, this page will introduce you to some of the language of rocks and minerals. Some of the words may look big, but they are useful because they describe a property , or something special, about that rock or mineral. The larger your vocabulary of these words, the better you will be able to understand rocks and minerals. Let's define a mineral and a rock, noting the differences between the two. A mineral is a natural substance which has its own distinctive structure and may have its composition expressed with a chemical formula.
Some examples are quartz, calcite, and galena.
Quartz has the chemical composition Si02. A rock is usually composed of 2 or more minerals in some physical combination, although some rocks are composed of only one mineral. Examples of rocks are limestone, sandstone, granite, or shale. About 100 minerals are relatively common. There have been over 4000 minerals identified by mineralogists, but only about the hundred or so are easily collectable.