With its high pressure resistance, high erosion resistance,chemical resistance, frost strength basalt is a volcanic type of the gabro group. They are in black, fine grained, hard, dense, durable and dense batches form. İn nature they are found as blocks, veins and streams. They are in glassy dough and scattered crystal beacuse of quick cooling. One of the most interesting feature is they are formed as hexagonal columns. These columns came from cooled and shrinked magma streams. As it is so hard and durable Stone, it is used in every steps of the buildings, pavements, grounds, side covering, city roads, bridge building.Considering its physical and mechanincal properties basalt sotone can be used as aggregate in concrete.