The definition of gravel and rock

decorative gravels refers weathered rock by the water flow from the long-term particle transport is non-angular natural aggregates of 2 ~ 60mm. Sediments classification in one name. Often the symbol G represents. It refers to the average particle size greater than 1 mm of rock or mineral debris. Average particle size, can be broken down into the gravel, boulders, coarse gravel and fine gravel are three: the average particle size of 1-10 mm, called fine gravel; 10-100 mm, called coarse gravel; greater than 100 mm , called boulders. Gravel after cementation diagenesis, called conglomerate or breccia.
decorative rocks is a natural output with stable outlook mineral or glass aggregates, combined together in a certain way. It constitutes the material basis of the crust and upper mantle. By cause into igneous rocks, sedimentary and metamorphic rocks. Among them, the magmatic rocks by high temperature molten magma at the surface or underground rock formed by condensation, also called igneous rocks [5]. He said discharge surface magmatic extrusive rock or volcanic rock, underground condensed called intrusive rocks.