--- product_id: 219854530 title: "NATIONAL GEOGRAPHIC Rock Tumbling Media – GemFoam Reusable Rock Polisher Foam, Use After Rock Tumbling Grit Cycles, Adds Shine to Tumbled Rocks and Minerals, Rock Tumbling Supplies" brand: "blue marble" price: "€ 41.03" currency: EUR in_stock: true category: "Blue Marble" url: https://www.desertcart.hr/products/219854530-national-geographic-rock-tumbling-media-gemfoam-reusable-rock-polisher-foam store_origin: HR region: Croatia --- # 3-day polishing duration Up to 6 reuse cycles Compatible with any tumbler NATIONAL GEOGRAPHIC Rock Tumbling Media – GemFoam Reusable Rock Polisher Foam, Use After Rock Tumbling Grit Cycles, Adds Shine to Tumbled Rocks and Minerals, Rock Tumbling Supplies **Brand:** blue marble **Price:** € 41.03 **Availability:** ✅ In Stock ## Summary > 💎 Elevate your rock game—shine like never before! ## Quick Answers - **What is this?** NATIONAL GEOGRAPHIC Rock Tumbling Media – GemFoam Reusable Rock Polisher Foam, Use After Rock Tumbling Grit Cycles, Adds Shine to Tumbled Rocks and Minerals, Rock Tumbling Supplies by blue marble - **How much does it cost?** € 41.03 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/219854530-national-geographic-rock-tumbling-media-gemfoam-reusable-rock-polisher-foam) ## Best For - blue marble enthusiasts ## Why This Product - Trusted blue marble brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Award-Winning Quality:** Created by Blue Marble, Toy of the Year winner, ensuring trusted STEM educational fun. - • **Unmatched Shine Boost:** GemFoam delivers a brilliant polish that elevates your rocks to museum-quality gleam. - • **Effortless Integration:** Simply add after your final grit cycle for a hassle-free shine upgrade. - • **Long-Lasting & Reusable:** Use GemFoam up to 6 times—maximize value while minimizing waste. - • **Universal Compatibility:** Works seamlessly with any durable rock tumbler, especially National Geographic tumblers. ## Overview National Geographic’s GemFoam is a reusable rock polishing foam designed to add exceptional shine to tumbled rocks after the final grit cycle. Compatible with all durable tumblers and reusable up to six polishing cycles, it offers an easy, cost-effective way to achieve professional-grade polish. Developed by award-winning Blue Marble, this product supports STEM learning and creativity for ages 8 and up. ## Description desertcart.com: NATIONAL GEOGRAPHIC Rock Tumbling Media – GemFoam Reusable Rock Polisher Foam, Use After Rock Tumbling Grit Cycles, Adds Shine to Tumbled Rocks and Minerals, Rock Tumbling Supplies : Industrial & Scientific ## Features - A BRAND NEW WAY TO MAKE TUMBLED ROCKS SHINE – GemFoam is a unique new rock polishing media that gives unprecedented shine to tumbled rocks. Just add the patent-pending rock polishing media to your tumbler after the final grit cycle for great results! - A LITTLE GOES A LONG WAY – Add a pack of GemFoam to your rock tumbling arsenal and use for multiple tumbling projects. GemFoam is reusable for up to 6 rock polishing cycles and comes with a convenient reusable bag made of mesh for easy storage. - WORKS WITH ANY ROCK POLISHER - GemFoam is safe to use with any durable tumbler. For best results, use with our National Geographic line of tumblers and rock tumbling supplies, like our ceramic media, tumbling grit, and rock refill packs. - EASILY IMPROVE YOUR ROCK TUMBLING RESULTS - When your final rock tumbling grit cycle is complete, add GemFoam, water, and the rocks you'd like polished back to the tumbler and tumble up to 3 days. Rocks will will come out with polish and shine! - AWARD-WINNING PRODUCTS - Blue Marble, winner of the Toy Association's prestigious Toy of the Year Award, proudly develops products that foster education, imagination, and creativity, with a U.S. support team to ensure a stellar experience! ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B08B7DJTCR | | Age Range Description | 8 years and up | | Best Sellers Rank | #800 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #1 in Tumbling Media | | Brand Name | Blue Marble | | Color | Black | | Customer Reviews | 4.7 4.7 out of 5 stars (18,681) | | Educational Objective | STEM | | Global Trade Identification Number | 00816448027451 | | Included Components | GemFoam Reusable Rock Polisher Foam | | Indoor Outdoor Usage | Indoor | | Is Assembly Required | No | | Item Dimensions | 4.72 x 1.18 x 7.28 inches | | Item Type Name | Rock Tumbling Media GemFoam Reusable Rock Polisher Foam | | Manufacturer | JMW Sales, Inc. | | Manufacturer Maximum Age (MONTHS) | 1188 | | Manufacturer Minimum Age (MONTHS) | 96 | | Manufacturer Part Number | NGFOMBAG | | Material Type | Foam | | Model Number | NGFOMBAG | | Number of Players | 1 | | Operation Mode | Manual | | Power Source | Manual | | Set Name | Single Set | | Size | Medium | | Sub Brand | National Geographic | | Supported Battery Types | No batteries required | | Theme | Rock Tumbling | | UPC | 816448027451 | | Unit Count | 1.0 Count | ## Images ![NATIONAL GEOGRAPHIC Rock Tumbling Media – GemFoam Reusable Rock Polisher Foam, Use After Rock Tumbling Grit Cycles, Adds Shine to Tumbled Rocks and Minerals, Rock Tumbling Supplies - Image 1](https://m.media-amazon.com/images/I/91Rp1wQXT4L.jpg) ## Available Options This product comes in different **Style** options. ## Frequently Bought Together - Blue Marble National Geographic Rock Tumbling Media – GemFoam Reusable Rock Polisher Foam, Use After Rock Tumbling Grit Cycles, Adds Shine to Tumbled Rocks and Minerals, Rock Tumbling Supplies - 2 LBS Rock Tumbling Ceramic Filler Medi Rock Tumbling Ceramic Filler Media Non- Abrasive Ceramic Pellets for All Type Tumblers 3/16" X 3/8" - 3LB Rock Tumbler Grit and Polish Refill Set, 4-Step Professional Polish Rock Tumbler Grit to Unlock Stunning Polished Stones. Ideal for National Geographic, KomeStone, and Other Polishers and Tumblers --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hr/products/219854530-national-geographic-rock-tumbling-media-gemfoam-reusable-rock-polisher-foam](https://www.desertcart.hr/products/219854530-national-geographic-rock-tumbling-media-gemfoam-reusable-rock-polisher-foam) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-07-14*