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

High quality rock tumbler made out of strong plastic and metal. The tumbler jar is made of rubber so it is quieter than most and will last a long time. It is a good beginners tumbler with a pretty small tumbling jar. I wish it was bigger. A nice set it and forget it mentality. You push the button for duration and it stops when the time is up. I took it out of the box and used it. not too much set up. It comes with a screen and all the grit you will need for one batch.

I originally purchased this in March 2024. I used it pretty regularly for 9 months and it worked wonderfully and I loved the results I got with my rocks. I paused using it for a few months and when I tried to start tumbling some rocks again, the tumbler would barely start moving and then would stop all together. Opening it up and cleaning it up seemed to help for a few minutes but then it would stop again. I opened it again and the connections all seemed fine but I wondered if the motor was just worn out. I contacted the manufacturer Think Blue Marble and they immediately replied to my email saying that it sounded like it was a weight sensor issue. They offered to send me a one time replacement free of charge! I provided my address and within 72 hours of my initial email I had received a brand new natgeo tubmler set in the mail! 100 stars for amazing customer service and standing behind their product! I'm just about to finish up the first stage in this new tumbler. Thank you Think Blue Marble!!

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!

This rock tumbler works great. I haven’t tried any others so I’m not sure how it compares. It’s pretty loud when it runs so we usually put it in a room that we don’t use very often. The instructions were pretty easy to follow and it looks just as pictured. The rocks don’t come out as shiney as the pictures show. I read somewhere that using mineral oil will make them shine. That might be something that could be added to the kit.

After only 5 months of use the motor quit. I followed all the directions exactly and didn’t overload the barrel. National Geographic’s supplier of this rock tumbler was quick to respond and replaced the unit immediately!

I had bought this tumbler July 2025 and some part of the motor ended up breaking this April 2026. I was saddened by this and did a little research and contacted National Geographics/ BlueMarble. They had sent me a new tumbler in the mail which came in 2 days after emailing them. That is outstanding customer service. This tumbler may not be the best for several reasons which include a general consensus that the barrel spins too fast for tumbling, you have to buy your own grit after the first run, the grit they give you wont make it shiny, and the rig may not be the most durable or long lasting. With all that said I will give this tumbler a pass because its just a starter, was easy and convenient to purchase, and they have good customer service.

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!

I haven’t seen a review (yet) that’s mentioned using this rock tumbler to tumble/smooth sea/beach glass.. so here’s mine & I hope this helps someone out there :) If you’re interested.. I’ve collected so much glass over my years of searching on Lake Erie. Majority of my glass is smooth or frosted over (chef’s-kiss kinda pieces), but of course I have not as-smooth pieces too. I know people say “it’s not ready,” but IMO, it’s ready if my bag is open and it’s not a literal shard of glass lol. Anyways. I’ve heard of people DIYing their own “sea” glass. I FINALLY purchased this, after 2 years of just thinking about getting one. Here’s how I feel about it (using beach glass, not rocks): So far, I’ve been using it almost night & day for about 1-2 weeks. 100/10. If you don’t have a basement, garage, or shed with an outlet, just know it’s a loud & noisy thang! It does wonders for my unfinished beach glass! I only left those pieces in the tumbler for 10-12 hrs (I believe), and they’re perfect now!! Lastly, we listen and we don’t judge: I didn’t read too far into the “what’s included” section, so I was honestly just expecting the tumbler 😂. I love that it came with necklace options, the rocks themselves, an extra rubber- chain(?), and the 4 grit packets. You certainly get your money’s worth. If you made to the end, thanks for taking the time to learn more! :)

ممتاز

Excellent product and 100% results producer but now a days this product buy on Amazon is totally foolish idea because very very expensive compared to original cost in USA. Dear buyers don't buy this product.

Sirve muy bien, sólo que es bastante ruidoso, y como tiene que estar prendido por días, llega a ser molesto

conforme à la description,notice claire et bien détaillée. Silencieux ! Rien à redire.

great value and product