---
product_id: 256324920
title: "National Geographic (Bulk Grit Media) - Rock Tumbler Grit - 1.5kgs Rock Polishing Grit Media, Works with any Rock Tumbler, Rock Polisher, Stone Polisher, Polishes 8-4.5kg of Rocks"
brand: "blue marble"
price: "$133.46"
currency: USD
in_stock: true
reviews_count: 5
category: "Blue Marble"
url: https://www.desertcart.us/products/256324920-national-geographic-bulk-grit-media-rock-tumbler-grit-1-5kgs
store_origin: US
region: United States of America
---

# 1.5 kg bulk refill for 8-10 lbs rocks Wide-mouth screw-top containers 4-stage silicon carbide grit system National Geographic (Bulk Grit Media) - Rock Tumbler Grit - 1.5kgs Rock Polishing Grit Media, Works with any Rock Tumbler, Rock Polisher, Stone Polisher, Polishes 8-4.5kg of Rocks

**Brand:** blue marble
**Price:** $133.46
**Availability:** ✅ In Stock

## Summary

> 💎 Transform Rough Rocks into Polished Masterpieces—Join the Rock Tumbler Elite!

## Quick Answers

- **What is this?** National Geographic (Bulk Grit Media) - Rock Tumbler Grit - 1.5kgs Rock Polishing Grit Media, Works with any Rock Tumbler, Rock Polisher, Stone Polisher, Polishes 8-4.5kg of Rocks by blue marble
- **How much does it cost?** $133.46 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/256324920-national-geographic-bulk-grit-media-rock-tumbler-grit-1-5kgs)

## 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

- • **STEM-Approved Fun:** Backed by National Geographic’s trusted STEM series, combining educational value with hands-on rock polishing excitement.
- • **Universal Compatibility:** Works seamlessly with any rock tumbler, but optimized for National Geographic tumblers for best results.
- • **Precision Polishing Power:** Four-stage grit system sculpts, smooths, pre-polishes, and shines your stones to perfection.
- • **Effortless Measurement & Storage:** Includes a 10 mL scoop and secure screw-top containers for mess-free, accurate grit dosing and easy storage.
- • **Bulk Supply for Endless Creativity:** 1.5 kg of premium grit media lets you polish up to 10 lbs of rocks, gems, and glass—no frequent refills needed.

## Overview

The Blue Marble National Geographic Bulk Grit Media is a high-quality, four-stage silicon carbide grit kit designed to polish up to 10 lbs of rocks, gems, and glass. Compatible with all rock tumblers, it features easy-to-use, wide-mouth containers with screw-top lids and includes a precise 10 mL scoop for accurate grit measurement. Perfect for STEM enthusiasts and hobbyists alike, this bulk pack ensures long-lasting polishing power and professional results.

## 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: 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: Indispensable pour utiliser la polisseuse de mon fils. Il y a de quoi faire pour un moment.

## Features

- HIGH QUALITY – This rock polisher grit refill pack comes with enough high-quality silicon carbide grit to put a dazzling polish on approximately 8-10 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
- SATISFACTION GUARANTEED – The National Geographic STEM series provides high-quality products that are a whole lot of fun! If your experience is anything less than extraordinary, let us know so we can make it right for you

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B01MRKI4W0 |
| Assembly Required | No |
| Batteries Included? | No |
| Batteries Required? | Yes |
| Best Sellers Rank | #59,854 in Kitchen ( See Top 100 in Kitchen ) #807 in Tumblers & Water Glasses |
| Color | Black |
| Customer Reviews | 4.6 4.6 out of 5 stars (13,593) |
| Date First Available | 12 January 2017 |
| Educational Objective(s) | Learn About Rock Tumbling |
| Item model number | NGBULKGRIT |
| Language | English |
| Manufacturer recommended age | 8 years and up |
| Material Type(s) | Carbide of Silicon |
| Number of Game Players | 1 |
| Product Dimensions | 13.97 x 13.97 x 10.8 cm; 1.78 kg |
| Radio Control Suitability | home |
| Remote Control Included? | No |
| tech_spec_battery_description_toys | No batteries required |

## Images

![National Geographic (Bulk Grit Media) - Rock Tumbler Grit - 1.5kgs Rock Polishing Grit Media, Works with any Rock Tumbler, Rock Polisher, Stone Polisher, Polishes 8-4.5kg of Rocks - Image 1](https://m.media-amazon.com/images/I/91eEtrXZOeL.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

### ⭐⭐⭐⭐⭐ Review
*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

### ⭐⭐⭐⭐⭐ Review
*by L***E on 22 January 2025*

Indispensable pour utiliser la polisseuse de mon fils. Il y a de quoi faire pour un moment.

### ⭐⭐⭐⭐⭐ Review
*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

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-03-14*