There are several types of pontils found on handmades. three of the more common are melted, ground, and what is commonly believed to be the oldest is ground faceted. If you look closely at this style you will see the pontil is ground at several angles giving it a clean finished look. this obviously took a better craftsman and more time than simply grinding it off. it is believed that the earlier makers used this method. as time went on they started just quickly grinding them off and then even later it is believed as the demand of production increased they began to squish the heated pontil on a flat surface as a finish and did away with grinding giving us a melted pontil. This is the accepted progression but not really any absolute proof of all this. The faceted pontil marbles do tend to be valued a little higher on the market.