There's that "somehow" method again! Somehow, they carved this diorite vase from primitive tools. Look at the handles on that. How long would it take to drill those using a wooden stick with a stone or metal blade attached? And what kind of metal? Copper or bronze, possibly iron. Regardless, it would be a lot of work for one pretty vase. And in the end, would you wind up with something so perfectly symmetrical? This looks as if it were cast in a mold, or 3D printed, or something. Certainly not painstakingly pounded out of a block and then hammered into shape.