Slate (also called stone of Lavagna) is a metamorphic rock of sedimentary origin (Metamarna pumpellyite-actinolite facies).
It is a variety of limestone and shale split easily into thin sheets, flat, lightweight, waterproof and weather-resistant, resulting from low-grade metamorphism of sedimentary rocks formed by deposition of a fine silt (marl) due to erosion of ancient reliefs. Slate is a rock classified as soft or semi-hard. It is a compact stone, leaden-blackish color and easy to work. The slate tends to clear from their extraction up to take a light gray pigmentation, the darker shade being due to carbon residues which oxidize when in contact with oxygen, moisture and ultraviolet radiation. By virtue of its schistosity (ie the ability to divide into slabs according to the cleavage planes due to its foliation) and properties, can be employed in various craft and industrial segments both architecture and construction (for the construction of roofs, floors, steps of stairs) and in art in the design and shelf everyday.