It is generally called native silver, that's what it looks like after it is removed from the surrounding rock, copper and gold commonly are also found that way. can't seem to find my pictures of mine. They call it leaf in the shops that sell souvenirs in the mining areas .Most rock shops stick with native silver name as that is what rock hounds known it by. It used to be sold by the size of the piece. Now it is by the weight with a premium added, depending on what the collectors are willing to pay at the shop