Whether an element is classified as a major or as a trace mineral is determined by

Whether an element is classified as a major or as a trace mineral is determined by " the amounts daily required by the body".

Calcium, magnesium, phosphorus, potassium, chloride and sulfur are all examples of the major minerals and these are the minerals a body needs in large quantity as opposed to include iron, copper, zinc, manganese, fluoride, selenium and cobalt, which are all trace minerals and are needed in very little quantity.