Slate industry in Spain keep cutting machinery cool. After quarrying regional authorities often dictate that the landscape is returned as much as possible to its original state, and waste rock left as part of the extraction process is returned adjacent to the quarry Slate industry in Spain 90% of Europes's natural slate used for roofing originates from the slate industry in Spain, with the region of Galicia being the primary source of production. Slate is a fine-grained metamorphic rock that splits into thin, smooth-surfaced layers. Metamorphic rock is rock which was once igneous or sedimentary and has been subsequently subjected to heat and pressure
Slate Parts of France (Anjou, Loire Valley, Ardennes, Brittany, Savoie) and Belgium (Ardennes), Liguria in northern Italy, especially between the town of Lavagna (which means "chalkboard" in Italian) and Fontanabuona valley; Portugal especially around Valongo in the north of the country. Germany's Moselle River region, Hunsrück, Eifel, Westerwald, Thuringia and north Bavaria (with a former mine open as a museum at Fell); and Alta, Norway (actually schist, not a true slate). Some of the slate from Wales and Cumbria is colored slate (non-blue): purple and formerly green in Wales and green in Cumbria. Slate is abundant in Brazil, the world's second-biggest