The things you put in to the tumbler especially to polish the rocks in the final phase will likely be made of cerium oxide, tin oxide, chrome oxide, or aluminum oxide. It's really a form of grit historically generally known as a polishing compound and is amazingly high-quality. More Wonderful https://www.facebook.com/permalink.php?story_fbid=pfbid02CgAiVhZ4NSBg2uWJKv63dv2DiJ5boogSePEZHkVQmLVuEt7nUkYQj8Xa9tQHUAS6l&id=61562415773754&__cft__[0]=AZU7soqQRdi0-0z9paHiW1AUpnanPyDpEYLt-mj6wO2WbgCSws1klflwE0lBk0y87B6A9V3KBp6FYTS22w3irYlKtuO6xSAJW6nKk3y26fZNbGhJ441al1yPgRjjzL8Uvm1zM-JEMjujjIbyNY-TSNPyxOJfJFXxRkiMbjEwtV87ZerSmjT9OzixT_TScDwp9IydE1dFym7njNtshdjIOhya&__tn__=%2CO%2CP-R