small gem crack fits: aqua, pebbles, tourmalines, larimar, and morganite
med gem crack fits: peridot, iris agate, emerald, zircon, bismuth, bixbite, lapis, and garnets
round gem crack fits: quartzes, jaspers, sapphire, ruby, topaz, obsidian, pearls, jade, agates, spinel, and spodumene
special gem crack fits: rutile.