Sedimentary Rocks (suisei-gan): Characteristics: Smooth and round, often layered, formed from sediments. Uses: Commonly placed along pond edges and used as stepping stones, enhancing the garden's tranquil aesthetic. Igneous Rocks (kasei-gan): Characteristics: Formed from cooled magma or lava, can be rough and porous (volcanic) or hard and coarse (plutonic). Uses: Ideal for symbolizing mountains or rugged terrain, and used as structural highlights or stepping stones. Metamorphic Rocks (hensei-gan): Characteristics: Transformed by heat and pressure, dense and often rich in unique patterns. Uses: Used around waterfalls and streams, providing durability and visual interest. Each rock type is selected for its natural appearance and symbolic significance, contributing to the garden’s harmony and philosophical expression.