About This

• RANKED #1 BY LEADING REVIEWERS — TRUSTED BY THOUSANDS OF FAMILIES: The KomeStone K1 Rock Tumbler was ranked the #1 Rock Tumbler by top independent product reviewers, recognized for performance, safety, and value. This gives parents confidence during holiday gift shopping, especially for STEM-minded kids and family creators.
• - & - : Enjoy peace of mind with our extended 90-day refund guarantee and 1-year warranty. If you miss Amazon’s 30-day return window, simply contact our US-based customer service for hassle-free replacement or refund assistance. We provide 24/7 claim support to ensure a smooth rock tumbling experience and complete customer satisfaction.
• SAFE FOR KIDS – CERTIFIED NON-TOXIC AND FAMILY FRIENDLY: KomeStone rock tumblers enjoys the CPC certification (Children's Product Certificate) issued by the federal government, and made from non-toxic, child-safe materials, ensuring a fun and educational STEM learning experience parents can trust. Smooth edges, secure closures, and low-noise operation make it a safe and engaging rock tumbler gift for curious young explorers.
• DIVE INTO THE FUN ROCK TUMBLING: KomeStone rock tumbler turns rough rocks into smooth gemstones through a real 4-stage tumbling process. Kids love watching each cycle’s transformation—a great patience lesson—and adults enjoy using polished stones for jewelry making and DIY crafts.
• 2025 NEW UPGRADE & ADVANCED FEATURES: Elevate your tumbling with a built-in LCD screen, 9-day timer, 3-speed controls, and pause/resume function. The thickened rubber barrel increases durability and improves noise reduction, while our custom polishing recipes help produce brighter, professional-level gemstones.
• 2.5 LB EXTRA LARGE CAPACITY & QUIETER: Our 100% soft rubber barrel absorbs impact for 75% quieter operation (similar to a dishwasher). The large-capacity design polishes 2.5× more rocks than standard 1 lb barrels—ideal for families, classrooms, and serious rock tumbling hobbyists.
• COMES WITH EVERYTHING YOU NEED: Includes tumbler, rubber barrel, 1 lb rough rocks, extra belts, 4 polishing grits, ceramic media, and an easy full-color guidebook—simple enough for any starter rock tumbler user to begin tumbling independently.
• SCIENCE-BACKED POLISHING FOR PRO-LEVEL RESULTS: Achieve museum-quality shine through our 4-stage grit system (60/120/150/1200) and precision ceramic media. The leak-proof stainless-steel lid ensures a clean, mess-free tumbling cycle, and our exclusive guidebook teaches pro polishing techniques for advanced users.
• About KomeStone: KomeStone rock tumblers are the first with brushless motor technology and now lead U.S. sales by a wide margin. We are more than a manufacturer — we’re your partner, offering reliable products and lifetime support you can count on.