Vibratory versus rotary tumblers: which one actually fits your goals

Rotary tumblers roll stones over each other inside a turning barrel, which produces very rounded, smooth shapes but takes longer overall, often four to six weeks start to finish across all grit stages. Vibratory tumblers vibrate the stones rapidly against each other in a bowl instead of rolling them, which cuts noticeably faster and preserves more of the stone's original shape and flat faces, which many people prefer when the goal is gem grade rough meant for cabbing rather than smooth tumbled pebbles. Vibratory cycles per stage are usually only a few days each rather than a week or more. The tradeoff is that vibratory units tend to be louder and can be less forgiving with very mixed or oddly shaped material. A lot of hobbyists start with a rotary tumbler because it is more forgiving for a first batch of assorted stones, then add a vibratory unit later once they are working with better rough.