Manufacturing slate starts by finding quality stone and creating a large slate quarry. The raw material is removed from the earth using large heavy equipment. Slate is composed of minerals, and could also contain calcite, quartz, feldspar, dolomite and other minerals. It is then manufactured into a piece of construction material to be used as products such as a tile , shingles for a roof or siding for your home. When buying slate from it is important to ensure you have a slate inspection and it is being tested with the proper ASTM tests, and the qualified quality control specialists.