1BK16 How to Tumble Polish Rocks into Gems — Secrets of the Pros Revealed; by Edward E. Smith, inventor of the Vibra-Sonic and Mini-Sonic Rock Tumblers.  This book has exclusive special sections about Abrasives, Media, Balancing loads, Cleaning, Sorting, Organics, Metals, Rotary, Vibratory, Wet or Dry Polishing and hundreds of other Tumbling Tips.  Copyright 3rd Edition 2005.