Quartz is a type of metamorphic rock formed from the mineral quartz by heat and pressure. Quartz is a rock-forming mineral and the second most common mineral in the Earth’s continental crust. The denseness and hardness of quartz make it ideal for use in bearings and cutting tools. The quartz stone or quartz marble slab is a type of quartz. A mineral that is part of the seventh group of minerals known as silicate minerals. These are mainly found in the sedimentary rocks of igneous, metamorphic. And sedimentary origin and in some metamorphosed sedimentary rocks—the mineral forms in clusters or aggregates of various shapes and sizes. The aggregated form is called marble.