---
product_id: 74202849
title: "National Geographic Hobby Rock Tumbler Kit - Rock Polisher for Kids & Adults, Noise-Reduced Barrel, Grit, 2.5 Pounds Raw Gemstone & Jasper Mix, Great STEM Hobby Kit"
brand: "blue marble"
price: "1148 Lei"
currency: RON
in_stock: true
reviews_count: 8
category: "Blue Marble"
url: https://www.desertcart.ro/products/74202849-national-geographic-hobby-rock-tumbler-kit-rock-polisher-for-kids
store_origin: RO
region: Romania
---

# 2.5 lbs raw gemstone & jasper mix included 75% quieter noise-reduced barrel Durable motor built to last National Geographic Hobby Rock Tumbler Kit - Rock Polisher for Kids & Adults, Noise-Reduced Barrel, Grit, 2.5 Pounds Raw Gemstone & Jasper Mix, Great STEM Hobby Kit

**Brand:** blue marble
**Price:** 1148 Lei
**Availability:** ✅ In Stock

## Summary

> 💎 Polish your passion, rock your world!

## Quick Answers

- **What is this?** National Geographic Hobby Rock Tumbler Kit - Rock Polisher for Kids & Adults, Noise-Reduced Barrel, Grit, 2.5 Pounds Raw Gemstone & Jasper Mix, Great STEM Hobby Kit by blue marble
- **How much does it cost?** 1148 Lei with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.ro](https://www.desertcart.ro/products/74202849-national-geographic-hobby-rock-tumbler-kit-rock-polisher-for-kids)

## 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:** From the Toy Association’s Toy of the Year winner, designed to inspire creativity and scientific curiosity.
- • **Complete STEM Experience:** Includes 4 polishing grits, sifter, learning guide, and 2 lbs of raw stones for endless discovery.
- • **Set & Forget Convenience:** One-touch timer with automatic shutoff lets you focus on life while your gems get their glow.
- • **Whisper-Quiet Performance:** Noise-reduced, leakproof barrel runs 75% quieter than competitors—perfect for home or office.
- • **Effortless Gemstone Creation:** Transform rough rocks into dazzling polished gems with simple, one-touch operation.

## Overview

The National Geographic Hobby Rock Tumbler Kit is a durable, quiet, and easy-to-use rock polisher designed for kids and adults. Featuring a leakproof barrel that reduces noise by 75%, it includes 2.5 pounds of raw gemstones and jasper, four polishing grits, and a comprehensive learning guide. This award-winning STEM kit offers a hands-on educational experience that turns ordinary stones into stunning polished gems, making it a perfect gift for hobbyists and science enthusiasts alike.

## Description

Buy National Geographic Hobby Rock Tumbler Kit - Rock Polisher for Kids & Adults, Noise-Reduced Barrel, Grit, 2.5 Pounds Raw Gemstone & Jasper Mix, Great STEM Hobby Kit: Rock Tumblers - desertcart.com ✓ FREE DELIVERY possible on eligible purchases

Review: Bought for 13 year old - Amazing rock tumbler—turned rough stones into gorgeous polished gems! This tumbler is a total winner for beginners and hobbyists alike. It runs super quietly (barely noticeable even in the living room), stays cool during long cycles, and the barrel seals perfectly—no leaks or mess. I followed the standard 4-6 week process with the included grit/polish steps, and the results are stunning: dull, jagged rocks came out mirror-shiny and smooth. Easy to use and clean, the motor is strong and consistent—no stalling with a full load. Great build quality for the price—feels durable and reliable. My family loves checking the progress every week, and now we have a beautiful collection of tumbled stones for jewelry and display. If you’re into rockhounding or just want a fun, satisfying project, this is fantastic. Highly recommend!
Review: Genuine review after fully using it! - Are you wondering if it works well? It does! Any problems? None! Results? Incredible, I was truly shocked! Pros: Almost no assembly, at all. Extremely easy to understand the directions (Tumbling time will vary depending on the rocks. Don't let it scare you away when it says one phase should tumble for 6-8 days (I haven't had to tumble any that long! The longest has been 3 days). That being said, an extremely hard rock that's very jagged may need more time. Using the rocks they include, or your own collection of crystals/gemstones is a great route. A plain piece of gravel or a rock of that type is very hard and dense and may take more time (who wants polished gravel anyway though?) Extended project to do with children, lots of engagement. Because their are 4 different grit types with different purposes, the children get to return to their project, dump the rocks and check on the progress and start a new phase. It's a great opportunity to teach to teach about erosion, and show / explain what a rock looks like through millions of years of erosion and then further explain how incredible it is that we are doing this project together that mimics what nature does, we are polishing these rocks in a few weeks that takes millions of years to do in nature! It's a wonderful learning opportunity for children, as well as an extremely engaging project that although it may take quite some time for it to finish, the ongoing project itself is what makes it fun. Returning to the rocks and seeing the progress, (we actually started taking pictures each time we open it so then we can look back on the pictures and see how the rocks have changed!). I cannot say enough how great of a project this is for children to get them excited about science! Personally, I find this to be very satisfying regardless of children. This would be an extremely fun hobby for an adult as well, the above is not to say that this is a children only experience. Use or find or buy your own natural gemstones or softer rocks (look in River beds if you can!). Tumble them, polish them, and then make your jewelry or just save them to display. It's quite a satisfying feeling to see the project from beginning to end, and to know that the beautiful smooth shiny rocks were not store-bought, but that you did this with that with this machine! Cons: I've been through the tumbling process in full, twice now. I honestly cannot think of any cons at this point. It's not to say that no one has had issues, but the machine I received functions perfectly and I have had no issues with leaks or ill-fitting pieces, tearing of the belt or anything of this nature. I did take a very small amount of oil on my fingertip and lightly rub it on the belt to keep it lubricated, with the constant friction I could see how the belt can eventually wear down just like any other belt of this nature whether it's in a car or in a fan. So, keeping it very slightly lubricated will help with the health of the band. Should it break, the kid includes an extra belt and it is incredibly easy to repair, the belt is divisible and an outside piece of the equipment you simply take one off and put the other on there is no sophisticated way of connecting the belt, it is truly something my six-year-old could do with almost no instruction, so an adult will have zero issues with that! If you are interested in rock tumbling, or you just want a very fun project for your children to stimulate their interest in science or to just keep them busy using their imaginations (regarding the possibilities of what to do with the rocks, and imagining whether it will look like and the brilliant colors!) - then this is absolutely a perfect kit to start with. DO: Make sure to not put too many rocks. I've never filled mine more than one third of the way, and I wouldn't recommend doing more than that. The amount of rocks you can tumble at a time will vary depending on the size, but I also recommend not doing anything smaller than a dime because during the tumbling process it could crack and chip. I would also recommend not doing anything larger than a half dollar as well (height and width, and that'd be on the largest size). Remember, this is just the hobby edition. I do have to say though, the results are quite sophisticated for just a hobby edition! All in all, it's an excellent piece of equipment to buy if you're interested in rock tumbling but are unsure if you would stick to it or are not ready to spend a few hundred dollars on a professional Tumbler. ** I did read a few comments about the machine leaking, I have not had this problem at any point. Make sure you are putting on the inner lid correctly, as well as the top lid, then turning the black lid securing piece as tightly as possible. If you do end up having problems, I highly recommend exchanging instead of giving up, because I really have seen that it works and I just want everyone who wants to try this to have the experience I've had! It's been great fun. Wonderful purchase, no regrets!

## Features

- CREATE YOUR OWN GEMSTONES - Make any stone sparkle and polish everyday rocks into dazzling gemstones! This rock tumbler kit makes it fun and easy to turn rough rocks into beautifully polished gemstones, thanks to its simple operation and durable design.
- BUILT TO LAST - Our high-quality tumblers are made with a durable motor that’s designed to last for years. The leakproof rubber barrel reduces sound, making it 75% quieter than other plastic models. Makes an excellent STEM gift or activity for girls and boys!
- EVERYTHING INCLUDED - Tumbler, 4 polishing grits, sifter, Learning Guide, rough gemstones, PLUS 2 one-pound refill packs of rough gems and jasper stones.
- EASY TO USE - Simple instructions and one-touch settings make rock tumbling fun and easy. Control the number of days for each tumbling cycle with the one-touch timer and automatic shutoff feature, so you can set it and forget it. This is a great gift for kids!
- 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 | B07G9MWHGJ |
| Best Sellers Rank | #3,206 in Toys & Games ( See Top 100 in Toys & Games ) #1 in Kids' Rock Tumblers |
| Customer Reviews | 4.5 4.5 out of 5 stars (31,535) |
| Is Discontinued By Manufacturer | No |
| Item Weight | 7.99 pounds |
| Item model number | NGHOBBYBUN |
| Manufacturer | JMW Sales, Inc. |
| Manufacturer recommended age | 8 years and up |
| Product Dimensions | 17.52 x 6.5 x 8.66 inches |
| Release date | November 1, 2018 |

## Images

![National Geographic Hobby Rock Tumbler Kit - Rock Polisher for Kids & Adults, Noise-Reduced Barrel, Grit, 2.5 Pounds Raw Gemstone & Jasper Mix, Great STEM Hobby Kit - Image 1](https://m.media-amazon.com/images/I/81eRSHVQ+aL.jpg)

## Available Options

This product comes in different **Style** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Bought for 13 year old
*by N***E on January 29, 2026*

Amazing rock tumbler—turned rough stones into gorgeous polished gems! This tumbler is a total winner for beginners and hobbyists alike. It runs super quietly (barely noticeable even in the living room), stays cool during long cycles, and the barrel seals perfectly—no leaks or mess. I followed the standard 4-6 week process with the included grit/polish steps, and the results are stunning: dull, jagged rocks came out mirror-shiny and smooth. Easy to use and clean, the motor is strong and consistent—no stalling with a full load. Great build quality for the price—feels durable and reliable. My family loves checking the progress every week, and now we have a beautiful collection of tumbled stones for jewelry and display. If you’re into rockhounding or just want a fun, satisfying project, this is fantastic. Highly recommend!

### ⭐⭐⭐⭐⭐ Genuine review after fully using it!
*by M***E on May 26, 2023*

Are you wondering if it works well? It does! Any problems? None! Results? Incredible, I was truly shocked! Pros: Almost no assembly, at all. Extremely easy to understand the directions (Tumbling time will vary depending on the rocks. Don't let it scare you away when it says one phase should tumble for 6-8 days (I haven't had to tumble any that long! The longest has been 3 days). That being said, an extremely hard rock that's very jagged may need more time. Using the rocks they include, or your own collection of crystals/gemstones is a great route. A plain piece of gravel or a rock of that type is very hard and dense and may take more time (who wants polished gravel anyway though?) Extended project to do with children, lots of engagement. Because their are 4 different grit types with different purposes, the children get to return to their project, dump the rocks and check on the progress and start a new phase. It's a great opportunity to teach to teach about erosion, and show / explain what a rock looks like through millions of years of erosion and then further explain how incredible it is that we are doing this project together that mimics what nature does, we are polishing these rocks in a few weeks that takes millions of years to do in nature! It's a wonderful learning opportunity for children, as well as an extremely engaging project that although it may take quite some time for it to finish, the ongoing project itself is what makes it fun. Returning to the rocks and seeing the progress, (we actually started taking pictures each time we open it so then we can look back on the pictures and see how the rocks have changed!). I cannot say enough how great of a project this is for children to get them excited about science! Personally, I find this to be very satisfying regardless of children. This would be an extremely fun hobby for an adult as well, the above is not to say that this is a children only experience. Use or find or buy your own natural gemstones or softer rocks (look in River beds if you can!). Tumble them, polish them, and then make your jewelry or just save them to display. It's quite a satisfying feeling to see the project from beginning to end, and to know that the beautiful smooth shiny rocks were not store-bought, but that you did this with that with this machine! Cons: I've been through the tumbling process in full, twice now. I honestly cannot think of any cons at this point. It's not to say that no one has had issues, but the machine I received functions perfectly and I have had no issues with leaks or ill-fitting pieces, tearing of the belt or anything of this nature. I did take a very small amount of oil on my fingertip and lightly rub it on the belt to keep it lubricated, with the constant friction I could see how the belt can eventually wear down just like any other belt of this nature whether it's in a car or in a fan. So, keeping it very slightly lubricated will help with the health of the band. Should it break, the kid includes an extra belt and it is incredibly easy to repair, the belt is divisible and an outside piece of the equipment you simply take one off and put the other on there is no sophisticated way of connecting the belt, it is truly something my six-year-old could do with almost no instruction, so an adult will have zero issues with that! If you are interested in rock tumbling, or you just want a very fun project for your children to stimulate their interest in science or to just keep them busy using their imaginations (regarding the possibilities of what to do with the rocks, and imagining whether it will look like and the brilliant colors!) - then this is absolutely a perfect kit to start with. DO: Make sure to not put too many rocks. I've never filled mine more than one third of the way, and I wouldn't recommend doing more than that. The amount of rocks you can tumble at a time will vary depending on the size, but I also recommend not doing anything smaller than a dime because during the tumbling process it could crack and chip. I would also recommend not doing anything larger than a half dollar as well (height and width, and that'd be on the largest size). Remember, this is just the hobby edition. I do have to say though, the results are quite sophisticated for just a hobby edition! All in all, it's an excellent piece of equipment to buy if you're interested in rock tumbling but are unsure if you would stick to it or are not ready to spend a few hundred dollars on a professional Tumbler. ** I did read a few comments about the machine leaking, I have not had this problem at any point. Make sure you are putting on the inner lid correctly, as well as the top lid, then turning the black lid securing piece as tightly as possible. If you do end up having problems, I highly recommend exchanging instead of giving up, because I really have seen that it works and I just want everyone who wants to try this to have the experience I've had! It's been great fun. Wonderful purchase, no regrets!

### ⭐⭐⭐⭐⭐ Fun product and fantastic customer service! 👏
*by J***. on January 12, 2026*

This was very easy to use. As a first-time hobbyist, I've always wanted a rock tumbler, and the instructions and suggestions were very clear and easy to follow. I started making tumbled stone jewelry as gifts for friends, family, and the steady stream of caregivers and medical professionals my husband and I see on a daily basis. We are both disabled and I (despite my own issues) am my husband's main caregiver. Rock tumbling and making jewelry have become my escape from the daily chaos of our lives, my relaxation from my anxiety and chronic pain disorders, and something I can share that is uniquely mine. I've had this tumbler for a year now, and have enjoyed it immensely. Recently, however, the belt broke. Not a big deal but, since replacing the the broken belt with the included replacement belt, the unit was fine for a couple of weeks before it suddenly stopped one night in the middle of a 7-day tumble. I tried re-seating the canister and started it again, only for it to stop again (with all of the lights flashing) 30 seconds later. I looked online for any suggestions dealing with the issue, and came up with several possible things that could be causing the problem. I removed the belt and carefully cleaned the rotating pins. I cleaned between the base rollers and the buffer pads, and made sure no pet hair or dirt was built up anywhere that could be causing the stoppage. I removed the canister and removed half of the stones in case the weight was the issue. Despite all of this, the unit would not keep spinning, and kept "freezing " within minutes of restarting. Today is Monday 1/12/26. My husband is in the hospital due to an infection, and I am trying to catch up on some things I've been putting off due to time constraints. So, I called the customer service number listed on the box. Since the product was purchased from Amazon, I was able to supply the NatGeo/BlueMarble help desk associate with the date and order number of the unit. I was also able to give them the SEC/lot number information since I still have the box. I then found out that I was 13 days past the warranty/exchange period. Some companies would simply refuse any liability because it was past the warranty date, but not this one. After hearing my issue, what I had done to address the problem, and getting the pertinent information about my purchase of the item and the unit itself, they generously offered to replace the entire kit. I was definitely not expecting that, but it was a great surprise and absolutely made my day. In conclusion, the tumbler is great for a first-time or young user. The directions are easy to follow. The stones are beautiful, if a bit small, but perfect for jewelry or other things. There is an included booklet with sample pictures to help you identify your stones, which I found very helpful. Above all, NatGeo and Blue Marble are VERY responsive to any issues and actually stand behind their product, a rare find in today's marketplace. I highly recommend this product for young or beginner tumblers. It took me until my 57th birthday to get one, and I've been having a blast!

## Frequently Bought Together

- National Geographic Hobby Rock Tumbler Kit - Rock Polisher for Kids & Adults, Noise-Reduced Barrel, Grit, 2.5 Pounds Raw Gemstone & Jasper Mix, Great STEM Hobby Kit
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- My Book of Rocks and Minerals: Things to Find, Collect, and Treasure

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*Product available on Desertcart Romania*
*Store origin: RO*
*Last updated: 2026-02-25*