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

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!

I think we're like 6 months in on this thing and it's still going strong. I do think the band is getting loose but they supply a few replacements. SO KEEP THEM, YA NERDS. Because you're going to get kinda hooked on this stuff and it's pretty radical to collect rocks and make them your treasures. So, go forth and collect your precious gems, whatever they are, and throw them in this bad boy.Also, just do a search for rock tumbler medium, or whatever you can think of, and you'll find it when you need more. Because we did.

The media could not be loaded. The kit comes with a ‘single serving’ of sanding packets to do one cluster of rocks. Then you’ve got to fork out more money for grit (sand) if you want to do another batch. Takes a month (yes… I said a month) of loud tumbling around the clock for one set of rocks to be polished. Now thats just how it’s done no matter the device so I still gave it a high rating. But be aware…. It sounds like an air compressor or power washer running all day and night…. even in a separate level and room of the house. I even tried to plug it in the basement but it was still loud upstairs. Not jackhammer loud, but definitely louder than a washing machine or dryer if it was filled with shoes and tennis balls. Odd comparison, but I think most will understand. It’s rocks being tossed around which makes noise, but the motor is loud too. Turn up the volume on the video for an idea.

I think this is a great tumbler kit! I'm new at this hobby and this kit has everything including crystals to do 1 batch. 4 stages of grit included. Barrel is kind of smaller but seems to be a standard size from what ive learned. 2.5#s is a good amount of stones anyways. Very Simple- each stage runs for a week, rinse in between cycles and bam crystals! Super fun, low key project.- requires about 15 minutes if that a week to rinse and restart a cycle. I purchased the extra gems also but not necessity. The finished stones in my Pic are about a 1/3 of the 2 pounds i purchased so I've already started a 2nd batch. Tumbler is not too noisy, i keep it in my attached garage and don't hear it in my house- its on a table with a ledge too-recommended so it doesn't rattle off and fall and break. Does not really seem to move around tho anyways.Can't wait to go to lake huron to collect my own stones

This is a great quality tumbler. It’s does the job very well. Only drawback is it’s a bit small.

Great rock tumbler for making sea glass

purchased for my grand daughters, works well and no leaks, amazing how smooth it can make those rocks