Stone Fillers can be added to Jesmonite AC100 and AC300. You should use the ratio 2:1 Jesmonite Powder:Jesmonite Liquid (by weight) and then should add the Stone Filler at between 70% and 100% (by weight) to the total mixed Jesmonite. Remember the whiteness of the Jesmonite will make the finish paler than the original Stone Filler, however you can use Jesmonite Pigments to achieve the finish you are after.