Sharp sand

Sharp sand, also known as grit sand or river sand and as builders' sand when medium or coarse grain, is a gritty sand used in concrete and potting soil mixes or to loosen clay soil[1] as well as for building projects. It is not cleaned or smoothed to the extent recreational play sand is. It is useful for drainage.[2] It is an angular grained sand.[3] It was used in the production of brass.[4] It is now used in the building trade. Sand and gravel ridges known as eskers are a frequently used source.[5]