Sand is derived from many rock types some of which are calcium carbonate (limestone), aluminum silicate (feldspar) or silicon dioxide (quartz). Many products used in everyday life are made from sand. Different kinds of sand are used for varying industrial purposes.
Tunnel Boring Machine (TBM) A tunnel boring machine (TBM) also known as a "mole", is a machine used to excavate tunnels with a circular cross section through a variety of soil and rock strata. They can bore through hard rock, sand, and almost anything in between.