Do you have a picture of one? I cannot see a purpose of it being graduated as cone molds are classically used when most of what you are pouring off is slag or when you re-melt slag and flux it differently to get any remaining beads to coalesce into one bead which collects at the bottom of the cone.
There are basically 3 size cone molds commonly available, the assay cone mold, these are pretty small, about 2" across the top diameter and 1 1/2" deep. they usually come as either 2 alongside each other or as a line of 6 in a row. Next is the intermediate size is primarily for slag. It is 8" diameter and about 6" deep. This is a popular size. Finally the big boy is 19" in diameter and 14" deep. These are not something you lift up and move and they usually are purchased with a specially made steel wheeled dolly to move these about. All three of these type cone molds have smooth interior walls.