Minerals, by definition, are naturally occurring, inorganic crystalline solids with a set chemical composition. Rock products are also considered in this section.
Rocks are mixtures of different minerals.
Economically important examples of these include sands and gravels, crushed stone, dimension and facing stone. Fossil fuels are not included here because of their organic origin, and because our intense dependence on them means they deserve special consideration on their own. Mineral resources form the foundation of our industrial society and an understanding of their origin, uses, mining processes and availability is essential to making informed decisions about them.