What is rock salt and what is it used for?
Rock salt is used in a range of formats but is basically the mineral form of sodium chloride. When used for industrial purposes it is often referred to as halite. It is a major part of the grit that is spread on our roads every winter to help prevent the formation of snow and ice which can cause traffic problems.
Gritting salt is not the same as the salt we use to put on our food. It comes from underground salt mines and is a brown colour and looks like gravel.