Can any crystal/stone be used for any purpose?

Can any crystal or stone be used for any purpose? I have a couple that were given to me but I'm unsure of what type they are and how to use them. I was told that I should cleanse them and that I can use them for whatever purpose I'd like but that each crystal or stone has it's own healing ability and would work best if used for it's original healing ability. I know one of the stones is jasper. I have an amethyst necklace and I also have a necklace with turquoise, quartz and what looks to be jasper..any thoughts, advice would be appreciated. Thanks!