GEOL 1403Lab Exercise: Minerals: GEOL-1403.295: Lab: Physical Geology.

Definition of a mineral. Geologists define a mineral as any naturally occurring, inorganic solid, with an orderly crystalline structure and a definite chemical composition. 1. Naturally occurring. Minerals form through natural geologic processes. A mineral cannot be a manmade substance. A synthetic diamond or emerald is not considered a true mineral because it is not naturally occurring. 2. Inorganic. An organic substance is a compound composed mostly of oxygen, carbon and hydrogen where carbon atoms bond directly with hydrogen atoms. Simple sugar, carbohydrate and fat (Figure 1) are examples of organic substances. To be classified as a mineral, a substance must be inorganic. 3. Solid. Minerals are solid substances, not liquid or gas. 4. Crystalline. The atoms that make up a mineral are arranged in an orderly, repetitive manner. This orderly structure of atoms is reflected in the regularly shaped objects called crystals.