2026 Rock Tumbling Contest (Part 17): A Quick Clean & Stage 5 Begins!

It’s Week 16 of the 2026 Worldwide Rock Tumbling Contest, and we are cleaning out after our Stage 4 run. Our detour using 1,000-grit aluminum oxide is complete. While some folks in the lapidary community look for a subtle pre-polish "luster" at this stage, in my experience, the rocks stay completely dull until they hit the real polishing powders. They are, however, feeling perfectly smooth and ready to move on. Before jumping directly into our first true polishing grit, we are taking an extra preventative measure to protect the remaining batch: an intermediate borax cleaning run (sometimes called burnish). We pull out the digital microscope to check our ongoing surface pit and spy a tiny new pinhole that has opened up on our banded stone. After confirming the barrel is free of grit contamination and celebrating a week with zero stone breakage, we officially charge the barrel for Stage 5 with 8,000 aluminum oxide! *More From This Series* Part 16: https://youtu.be/iAOjWiNJGbc?is=X-4SVFGSTKMHqk1q Part 18: https://youtu.be/Jb_LopurtuM?is=R4mBvc4-h3CeY98T *Video Summary* We kick off the Stage 4 cleanout and dry off a few stones to see if the 1,000-grit aluminum oxide left behind any pre-polish luster. While they remain dull for now, they are perfectly smooth to the touch. We sort through our favorite dark patterned stones and check on our structurally vulnerable large rock to ensure its edges are holding up without any additional bruising. Next, we switch over to the digital microscope to track our problem areas. The main surface pit is looking clean and free of trapped grit, though close magnification reveals a tiny new pinhole and some stubborn white dots on the banded rock's surface. To guarantee a pristine environment for our upcoming polish, we load the barrel with a tablespoon of borax for a quick 1-hour clean cycle. After dumping out the cloudy rinse water—proving just how much hidden residue the burnish pulled away—we officially charge our Stage 5 run with 8,000-grit aluminum oxide and map out our final timeline for the remainder of the competition. *In This Video* - Stage 4 Cleanout & Debunking the 1,000-Grit Pre-Polish Luster - Inspecting Contest Contenders & Checking the Vulnerable Chipped Rock - Microscope Check: Clean Pits, Stubborn Surface Dots, & New Pinholes - Setting Up the Pre-Polish Borax Burnish (Why I Don't Do It Every Stage) - Revealing the Cloudy Burnish Water & Rinsing the Batch - Zero Breakage! Charging Stage 5 with 8,000 Aluminum Oxide Polish - Adding Borax & Projecting the Final Contest Timeline - The Shake Test: Listening for the Perfect Low-Movement Slurry Sound *Join the Fun* Feather River Lapidary & Mineral Society: https://www.featherriverrocks.org/ *Equipment* - Rotary Tumbler: Dual 3lb Central Machinery tumbler from Harbor Freight - Stage 5 Polish: 2 Tablespoons of 8,000 Aluminum Oxide - 1 Tablespoon of 20 Mule Team Borax - Media: Pre-Tumbled Ceramic Cylinders - Bench Tools: 50x–100x Digital Microscope Subscribe to follow my progress in the 2026 Worldwide Rock Tumbling Contest! #RockTumbling #FRLMS #Jasper #Lapidary #RockHounding #Stage5 #Geology #Microscope #AluminumOxide #RockPolish #RotaryTumbler #BoraxBurnish More updates and past batches at https://www.instagram.com/eyetumbleforya