Clay slate

Slate consists mostly of mica, quartz and clay minerals. It usually comes in gray or black color, occasionally you can also find it in greenish tones.

Slate is a fine-grained rock which is much harder than sedimentary slate. However, due to the high pressure and high temperatures, the clay slate has lost its ability to swell in water, which is typical for clay. Clay slate has the typical features of metamorphites, but belongs to the low metamorphic ones.

Clay slate is mainly used for roofing or wall cladding.