A rock is a naturally occurring solid aggregate of one or more minerals or mineraloids.This Collection contains 50 Types of Basic Rocks Specimens of Igneous, Sedimentary & Metamorphic Rocks Types. The Rock Specimens include Basalt, Diatomite, Gabbro, Gniess, Granite, Lime Stone, Marble, Obesidian, Quartizite, Rock Salt, Sand Stone & Slate etc.