Slate are crystalline rock formations, which have been heavily affected by metamorphosis, as they were formed mainly in the middle and lower zones of the universal transformation. The name shale, moreover, comes from the property that shows the rock being torn into slabs. In general, slate, like the gneiss, are the predominantly crystalline squamous rocks involved in the structure of a metamorphosed area. Shale building blocks are generally smaller than guts and larger than splitters and foliage. Coarse shale resembles the gnosis, but they are distinguished by the absence or presence of a small percentage of the astringent, while the fine shale is confused with the shingles and foliage. There are many types of shale geologically characterized by their predominant mineralogical component such as mica, quartz, doubtful shale, etc. Slate rich in calcite or dolomite usually accompany crystalline limestones (marbles) and are called limestone shale. From the mineralogical components of the shale, the quartz is found in thin layer-like interference, the thickness of which varies. In addition, the mica leaflets have a laminate arrangement parallel to the direction tilted to the rock. The mica shale consists mainly of quartz and mica and is distinguished by foliage only by the size of its structural units. In these schists, mica may be muscovite, biotite, paragonite (mica sodium) or sericite (hydrated muscovite). The mica shale originates mainly from the transformation of sandstone, clay, clays, old tufos and exploded rocks of granite or porphyry tissue.