The slate is a metamorphic rock of fine and homogeneous grain composed by clay or volcanic ashes that were metamorphosed in layers

The slate can be transformed in small sol, because it has two  lines of sheets: cleavage and grain. This makes possible a separation into thin sheets. Synthetic and manufactured coverings can, initially,  be cheaper in the placement, but the small sols slate will last many and many years, making this material a better choice in the future and more economical.

Other applications of the slate: Pavements, facades,  laboratory covers, and in interior and external decorations. Thin sheets  of black or dark gray slate were  the most used material in the production of black pictures, or flagstone. Nowadays, with the appearance of more appropriate materials,  the slate hasn't been used for this purpose anymore.

O Estado de Minas Gerais responde por 95% da produção de ardósia do Brasil. O município de Papagaios, sozinho, é responsável por metade da produção nacional de ardósia, e o Brasil, por sua vez, é o segundo maior produtor mundial. Em 2007, a cidade contava com 25 pedreiras e cerca de 200 indústrias de beneficiamento, que geram cerca de cinco mil empregos diretos e mais cinco mil indiretos.