Vermiculite 4 QT - Grade 4 Super Coarse Bagged 4 quart size. Just for the hobbyist that does not need a large 4 cu ft bag Grade 4 - Super Coarse. Great for potted plants Vermiculite is a natural mineral, permanent, clean, odorless, non-toxic and sterile Holds moisture and nutrients, leaving more room for air in the soil Promotes faster root growth and quick anchorage for young roots