Which mineral is formed by decomposition of rocks, leaving a residual mass weathered material? (CBSE 2014)

Bauxite is a mineral which is formed by decomposition of rocks, leaving a residual mass of weathered material.

NOTE – A naturally occurring homogeneous substance that has a definable internal structure is called a mineral. Minerals usually occur in various forms i.e. the various kinds of atmospheric conditions that play an important role in the formation of minerals.