Slate is a homogenous, fine-grained rock which is opaque and tough. It can be readily split into thin, flat sheets.
Nowaday, Spain is the number one slate producer of Natural Roofing Slate in the world, with an Export volume exceeding
80% of slate extracted in Galicia and Castilla y Léon. The slate
sector is one of the most important in the Northwest region of Spain. The volume of business
in the area gives jobs directly to more than 3,500 people and indirectly to 12,000 people.