--- product_id: 119836792 title: "National Geographic Grit Refill for Rock Tumbler - Works with National Geographic" brand: "blue marble" price: "$175.69" currency: USD in_stock: true reviews_count: 5 category: "Blue Marble" url: https://www.desertcart.us/products/119836792-national-geographic-grit-refill-for-rock-tumbler-works-with-national store_origin: US region: United States of America --- # 3+ lbs bulk grit for up to 20 lbs rocks Wide-mouth screw-top containers 4-stage silicon carbide grit system National Geographic Grit Refill for Rock Tumbler - Works with National Geographic **Brand:** blue marble **Price:** $175.69 **Availability:** ✅ In Stock ## Summary > ✨ Turn rough stones into polished treasures — your DIY gem journey starts here! ⚒️ ## Quick Answers - **What is this?** National Geographic Grit Refill for Rock Tumbler - Works with National Geographic by blue marble - **How much does it cost?** $175.69 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/119836792-national-geographic-grit-refill-for-rock-tumbler-works-with-national) ## 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 - • **Universal Compatibility:** Seamlessly works with all rock tumblers, optimized for National Geographic models for flawless results. - • **Precision Polishing Power:** Four distinct grit stages sculpt, smooth, pre-polish, and shine your stones to museum-quality brilliance. - • **Bulk Supply for Big Projects:** Over 3 pounds of premium grit lets you transform up to 20 lbs of rocks, gems, or glass in one go. - • **Award-Winning STEM Excellence:** From the Toy of the Year-winning Blue Marble brand, inspiring creativity and scientific curiosity. - • **Effortless Measurement & Storage:** Includes a 10 mL scoop and secure containers to keep your grit fresh and perfectly portioned every time. ## Overview The National Geographic Grit Refill is a premium 4-stage silicon carbide grit kit designed to polish and shape up to 20 lbs of rocks, gems, and glass. Compatible with all rock tumblers and optimized for National Geographic models, it includes over 3 pounds of grit, a precision 10 mL scoop, and secure storage containers. Backed by award-winning STEM educational expertise, this refill kit ensures professional-quality results for hobbyists and collectors alike. ## Description The National Geographic Rock Tumbler Grit Bulk Pack contains over 3 pounds of rock polishing grit, compatible with any rock tumbler!This Kit Includes:- 4 Stages of Rock Polishing Grit- 1 10 mL Grit Scoop- Rock Tumbling InstructionsThis four-stage silicon carbide grit for rock tumbling system is the ideal way to give rough rocks a smooth, polished look. The first rock polishing stage smooths rough edges and provides initial shaping. The second stage smooths the rock surfaces even more. The third stage provides a strong pre-polish, followed by the fourth stage which completes the grit polishing process.The 10 mL scoop in the grit refill kit ensures accurate grit measurements for every stage, allowing you maximize your grit usage for up to 10 pounds of rocks!This grit refill for rock tumbler pack is compatible with any rock tumbler on the market. But for best results, use this rock tumbler grit and polish refill with National Geographic rock tumblers and rock tumbling supplies, including ceramic media and GemFoam.National Geographic Toys makes the highest quality hands-on science toys, and all products are backed by exceptional service.About the National Geographic Society: With a mission to inspire people to care about the planet, the National Geographic Society is one of the world’s largest nonprofit scientific and educational organizations. Review: Helps Poshing - It helps shaping stones too..it is a little sound and I'm living 2floor so I put a box on it to make the noise more silent Review: Passt und erfüllt seinen Zweck - Passt und erfüllt seinen Zweck ## Features - HIGH QUALITY - This rock polisher grit refill pack comes with enough high-quality silicon carbide grit to put a dazzling polish on up to 20 lbs. of rocks, gems, glass, and more - EASY TO USE FOUR-STAGE ROCK GRIT - The first rock tumbling grit stage provides initial shaping, the second smooths rock surfaces, the third pre-polishes rocks, and the fourth provides the final polish - COMPATIBLE WITH ALL TUMBLERS - This complete 4-step rock tumbler grit refill kit works with all rock tumblers. For best results, use with National Geographic Rock Tumblers and rock tumbling supplies - EASY TO MEASURE AND STORE - Each rock tumbling grit stage is packaged in a wide-mouth container with secure, screw-top closure. - 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 | B01MRKI4W0 | | Battery Types | No batteries required | | Brand | Blue Marble | | Colour | white | | Customer Reviews | 4.6 out of 5 stars 13,728 Reviews | | Educational Objective | STEM | | Global Trade Identification Number | 00816448020636 | | Included Components | 4 Stages of Rock Polishing Grit, 10 mL Grit Scoop, Rock Tumbling Instructions | | Is Assembly Required | No | | Item Dimensions | 14 x 14 x 10.8 Centimeters | | Item Type Name | Rock Polishing Grit Media | | Item Weight | 1.78 Kilograms | | Manufacturer | JMW Sales, Inc. | | Manufacturer Part Number | NGBULKGRIT | | Material | Silicone | | Model Number | NGBULKGRIT | | Number of Players | 1 | | Operation Mode | Manual | | Size | One Size | | Sub Brand | National Geographic | | Theme | Rock Tumbling | | UPC | 816448020636 | | Unit Count | 1.00 Count | ## Images ![National Geographic Grit Refill for Rock Tumbler - Works with National Geographic - Image 1](https://m.media-amazon.com/images/I/91eEtrXZOeL.jpg) ![National Geographic Grit Refill for Rock Tumbler - Works with National Geographic - Image 2](https://m.media-amazon.com/images/I/81hedgBgXUL.jpg) ![National Geographic Grit Refill for Rock Tumbler - Works with National Geographic - Image 3](https://m.media-amazon.com/images/I/815lTl9gu5L.jpg) ![National Geographic Grit Refill for Rock Tumbler - Works with National Geographic - Image 4](https://m.media-amazon.com/images/I/81JbgcmUwDL.jpg) ![National Geographic Grit Refill for Rock Tumbler - Works with National Geographic - Image 5](https://m.media-amazon.com/images/I/91Pm3blguRL.jpg) ## Questions & Answers **Q: How many oz is in each container?** A: 1 Coarse-16oz. 2 Medium-13oz. 3 Pre-polish-12oz. 4 Polish-11.5 oz. **Q: I just opened this and finished with grit one, went to put grit 2 in and bottle open and 1/2 full. How do I contact seller?** A: I would go through Amazon to get an answer for your problem. **Q: Can it be used together ?** A: Each grit is a different fineness intended for a specific purpose. We do not recommend using them at the same time. We do recommend 1 TBS grit per per 1 LB rocks, at each cycle. For further information please contact us at help@natgeotoys.com. **Q: After each step for the rocks in the kit, my rocks dry with a dull white finish. It doesn't show when it is wet. Am I doing something wrong?** A: No. I find that after tumbling with the finest grit after the last step... and thoroughly allowing the rocks to dry, a nice coat of wax or oil brings out the color beautifully. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Helps Poshing *by F***M on 15 November 2021* It helps shaping stones too..it is a little sound and I'm living 2floor so I put a box on it to make the noise more silent ### ⭐⭐⭐⭐⭐ Passt und erfüllt seinen Zweck *by M***E on 11 January 2026* Passt und erfüllt seinen Zweck ### ⭐⭐⭐⭐⭐ Muy satisfecha *by A***X on 13 July 2025* El proceso de pulir piedras es algo largo, pero el producto hace su labor. Viene suficiente cantidad para varias tandas y es muy sencillo de usar, ya que cada paso esta numerado. ## Frequently Bought Together - Blue Marble National Geographic Rock Tumbler Grit and Polish Refill Kit - Tumbling Grit Media, Polish Up to 20 lbs. of Rocks, Works with Any Rock Polisher, Rock Tumbler Supplies - National Geographic Rock Tumbler Kit – Hobby Edition Includes Rough Gemstones, and 4 Polishing Grits, Great STEM Science Kit for Geology Enthusiasts, Rock Polisher for Kids and Adults - UU UNIHOM 3 lbs Bulk Rough Madagascar Stones Mix Large 1" Natural Raw Stones Crystal for Tumbling, Cabbing, Fountain Rocks, Decoration,Polishing, Wire Wrapping, Wicca Reiki Crystal Healing --- ## 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.us/products/119836792-national-geographic-grit-refill-for-rock-tumbler-works-with-national](https://www.desertcart.us/products/119836792-national-geographic-grit-refill-for-rock-tumbler-works-with-national) --- *Product available on Desertcart United States of America* *Store origin: US* *Last updated: 2026-07-12*