Everyone likes to classify things: by shape, by color, by cost, by size. You name something to sort by, and someone is busy classifying with it. So, it should be no surprise that geologists get classified. And perhaps the first way they get labeled is as either a soft rock geologist or a hard rock geologist. No, it has nothing to do with the character of their head (although some might disagree) and it has nothing to do with their taste in music. Rather it relates to the type of rocks they study.