This tumbling rough from California's wild Yuba River is primarily for the kids--the rocks are already sized and "partially processed" by Mother Nature and are ready for Stage #1--after just a week or two, you can move to Stage 2 with well shaped rock. Saves weeks in Stage 1. The resulting polished rock is mostly Quartz with some Jasper and Agate. Any kid will love this stuff! This is 5 Lbs of assorted Yuba River Mix in a bag at $2.50/Lb.