Slate (writing) Slate (writing) A slate is a thin piece of hard flat material, such as the rock also called slate, that is used as a medium for writing. The rock is “a metamorphic rock created by the recrystallization of the minerals in shale from clay to parallel-aligned, flat, flake-like minerals such as mica”. The writing slate consisted of a piece of slate, typically either 4x6 inches or 7x10 inches, encased in a wooden frame. A precise date range for writing slates of this type has not been established. Usually, a piece of cloth or slate sponge was used to clean it
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