What’s the difference?
Mineral: a naturally occurring substance that is formed through geological processes and has a characteristic chemical and physical composition. 
Minerloid: a mineral substance that does not have a definite chemical formula or crystal form. 
Rock / Stone: a natural substance, a solid aggregate of one or more minerals or mineraloids. 
Crystal: a solid whose atoms are arranged in a “highly ordered” repeating pattern. If a mineral has its atoms arranged in one of them, then that mineral is a crystal. 
Gemstone: a piece of mineral crystals, rocks, or organic materials that are not minerals that is cut and/or polished.