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![Solution features in sandstone. (© Marli Miller, University of Oregon) Solution features in sandstone.](https://www.americangeosciences.org/sites/default/files/styles/ci__650_x_430_/public/ERN_weathering_rocks_Miller_hhrhsr.jpg?itok=yvRm0A7r)
Rock is either broken into smaller particles (disintegration-physical weathering) or altered into other kinds of minerals (decomposition - chemical weathering). Although these processes do not occur in isolation, it is easier to understand them by considering them separately.