This is a five (5) pound bag of size coarse 60/90 silicon carbide grit for rock tumbling. It is AA quality and made in the USA. Coarse is usually the first step in the tumbling process although we do offer an extra coarse size 46/70 if your stones are exceptionally rough. You will want to run your stones anywhere from a week to five weeks and make sure they feel perfectly smooth before you move to the next step. After two weeks if the stones still feel rough, you can add a little more grit to the process. Take notes so you remember what and when and what kind of stones. Then clean well, and move on to the next stage of Step Two (medium size 150/220) to begin conditioning the stones to accept polish. The cleaning step must be done outside, never, never pour the sludge down your drains.