Talc Easily with fingernail Softest of minerals. Used in paint, paper, face and talcum powder. Gypsum Barely with fingernail Of considerable importance because of its use for plaster of Paris, wallboard, interior plaster.
Alabaster is a finegrained variety of gypsum.
Calcite Barely with copper penny Often used for optical prisms. Limestone and marble are varieties of calcite. A beautiful mineral occurring in many different colors. Chiefly used for making steel, it's also used in making opalescent glass, enameling cooking utensils and making hydrofluoric acid. Apatite Barely with knife blade Only one of the phosphate group to be considered a common mineral.