I do not know the answer. I do know many mineral specimens have other minerals incorporated in the specimen. Usually, the rock is officially a rock of a certain kind if it has the highest percentage of that rock in the specimen. For instance many agates are part of a matrix. To officially be considered an agate, it must be 50 percent agate but that does not preclude the specimen from being an agate because it has agate in it. Local names for rocks confuse the issue, but think about this, there are types of minerals that can be identified by which mine they come from. To give each a local name would be totally confusing.