Rocky Basing Grit is the chunkiest of the three grades of Basing Grit, & is usually used to represent rubble or debris. Rocky Basing Grit can also be mixed into Fine & Medium grits to add some texture to your bases.A note on our basing grit: All Gale Force Nine basing grit is made from a porous organic material rather than sand or other minerals. This organic material absorbs glue & paint, insuring that everything stays where you want it. When using sand (or kitty litter or any other mineral), paint & glue tend to flake off over time. Packaged in a round plastic container approx. 2.75 in diameter, 1 deep.