Unlike plaster powder which is mainly fine, Landscape plaster consist of both fine and assorted coarse particles. Only mixing with water to form a workable trowelling or casting application, it sets hard with rocks like features derived from the coarser particles. The finer plaster function as cementing mortar among the coarser rocks and can be erosion removed with a wet stiff brush to expose more rocks if required. Alternatively erode with fine wire brushing. As both fine and coarse particles are white it accepts color air brushing for realistic rocky landscape or cliff out-crop.
Do not mix with excessive amount of water as it sets soft and chalky. Use sufficient water for a trowellable consistency for cliff out-crops without slumping. You may also cast in small random clumps when set, assemble fix with plaster paste to form a rock cliff.