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💎 Turn rough rocks into dazzling gems—because your desk deserves a little sparkle!
The National Geographic Hobby Rock Tumbler Kit is a durable, noise-reduced rock polishing system designed for beginners and enthusiasts alike. Featuring a quiet rubber barrel, one-touch timer with auto shutoff, and a comprehensive kit including 2.5 pounds of raw gemstones and polishing grits, it offers a seamless STEM hobby experience for ages 8 and up. Award-winning and built to last, it’s the perfect blend of education, creativity, and fun.





| ASIN | B07G9MWHGJ |
| Age Range Description | 8 years and up |
| Battery Description | Alkaline |
| Best Sellers Rank | #2,051 in Toys & Games ( See Top 100 in Toys & Games ) #1 in Kids' Rock Tumblers |
| Brand Name | Blue Marble |
| Customer Reviews | 4.5 out of 5 stars 2,312 Reviews |
| Educational Objective | STEM |
| Global Trade Identification Number | 00816448025891 |
| Included Components | Rock Tumbler, 2 Packs Gemstones |
| Is Assembly Required | No |
| Item Dimensions | 17.52 x 6.5 x 8.66 inches |
| Item Type Name | Hobby Rock Tumbling Kit - Rock Polisher for Kids & Adults, |
| Item Weight | 7.99 Pounds |
| Manufacturer | JMW Sales, Inc. |
| Manufacturer Maximum Age (MONTHS) | 1188 |
| Manufacturer Minimum Age (MONTHS) | 96 |
| Manufacturer Part Number | NGHOBBYBUN |
| Material Type | Plastic,Rubber |
| Model Number | NGHOBBYBUN |
| Set Name | Hobby Rock Tumbler Kit |
| Size | One Size |
| Sub Brand | National Geographic |
| Theme | Rock Tumbling |
| UPC | 816448025891 |
| Unit Count | 1.0 Count |
H**H
Great for beginners
I have never done rock tumbling before but became interested when I found some quartz at my mother's house. She lives outside Marble Falls, Texas. I shopped around quite a bit and based off reviews alone, this was the best machine for beginners and for the price. I initially bought the one available at my local Hobby Lobby and it would leak a little water and get the belt wet. The belt system used runner teeth and after just one day of use the belt was no good and the machine would not run. With this brand the belt is smooth and operates based off tension just like the pullies in your car. The rubber barrel helps eliminate most noises. The motor is quiet, the only noise is from the machine is it vibrating on a solid surface. Mine walks a little, so make sure you have it on a level surface. I waited to do my review until I had used the machine a while. I have done two separate rounds with it. Everything runs great still after more than 2 months of continuous use. I can see that the belt will wear out before anything else. There are little flecks of the belt around the area the machine sits in. I believe there is some plastic on the pullies that may be wearing on it. It does come with an extra belt though. I am currently tumbling Tiger's Eye rocks. The pack comes with a variety of rock types. I am tumbling like rocks together just to make sure everything wears at the same rate. My only real complaint is that in all the rock packs, the amount of amethyst is rediculos. I was provided some, but the pieces were so small that they would be destroyed if tumbled. There are also too many dalmatian jasper stones compared with how many of any other stone there is. Overall I am content with how well it works.
J**S
Awesome Nat Geo Customer service!!
This was a great gift for our daughter. She loved it and and has gotten a lot of use from it. Recently it stopped working ( quit suddenly during cycles and all day lights flashing simultaneously) and I did some research to see if it was something I could fix. Found out there were some others that had the same issue. Some said it was the belt needing replaced or it was overloaded. We addressed these and the issue continued. Ended up reaching out to Nat Geo and explained the issue. They were amazing. The ended up replacing the unit for us and got my daughter tumbling again. Nat Geo products are a go to for us on birthdays and such for the fun and educational aspects they provide, along with the great family time and memories they have created. The customer service received will keep us buying their products! Thanks Nat Geo!
A**R
Fun for kids
This is really an incredible kit. The process takes time, but the end product is worth it. My kids loved watching the rocks change over time. The tumbler can be loud - we live in a small space so we heard it running. We polised the final rocks with some mineral oil to get a real shine.
M**A
Stem learning for KIDS. Small barrel, and is loud.
Update. Quit working just flashes lights. Good for small kids. Not good for someone wanting to tumble a large amount of stone. Comes with one small grit pack for stones it comes with and one in each pound of rocks. The rocks are crap. U get very little agate I got no amethyst, some pale amazonite, and the rest is various jasper. Oh did get a large chunk of sodalite that wont fit in tumbler. Tum let is NOISY!!! And it does take about 2 weeks to tumble stones so I advise u put it in the garage. Unless your in a cold climate because u must use water and grit to tumble stone. Also the jewelry it comes with, well all I can use are the cord for necklace.. u get 3 jewelry" kits" in this package. I can use the stone cages from the necklace and key chain, the earrings are clip ons that require an epoxy glue and same with the tiny adjustable ring. Honestly would have saved money buying a tumbler and bulk grit separate. All of this can also be found on wish. Just because it's a nat geo product doesn't make it better. The drum is all rubber with a stainless cap, and u get the base, plug, and an extra "belt" that's hidden under the cap. There are rocks in a bag inside the tumbler when u get it. None of jewelery quality. Lot of nice tigers eye chunks but u can buy that cheaper here or wish. If I wasnt a prime member and had to pay shipping.. this is 7+ pounds.. I would have not gotten it. It will work for now because ups was 3 days late from a snow storm. I'm starting Into lapidary and jewelry making so I'm sure I will get a lapidary wheel and bench as I improve. All jewelry findings can be found on amazon.
A**Z
Fun, Educational, and Easy to Use
This rock tumbler kit is a lot of fun and very easy to use. Everything needed to get started is included, and the instructions are clear and simple to follow. It’s a great hands-on activity and feels well made. Perfect for hobbyists, kids, or anyone interested in rocks and geology.
J**E
Days of fun!
Best gift for kids who love rocks! Everything you need to make them perfect! Awesome gift and DAYS of excitement for a great outcome
R**D
Great
My son looooooves it! Just put it in a room thematic isnt used much lol
M**N
Died just outside of the one year warranty
Worked great until it didn’t. I bought this in August of 2024. My daughter used it for the two gem sets that came with it. We bought another National Geographic gem set and she started tumbling last month. The tumbler just quit halfway into the third grit cycle. The roller isn’t seized and the rubber band is fine. The motor just isn’t driving the pulley wheel. I reached out to National Geographic’s customer service team explaining what was going on and was told the following: “Based on the information you provided, it sounds like the motor may be failing. We recently updated the motors used in our tumblers; however, we do not sell replacement motors separately at this time. Additionally, your item is outside of our one-year warranty period, so we cannot offer a replacement. We recommend reaching out to a local hobby or specialty store, as they may be able to assist with troubleshooting or possible repairs. We appreciate your understanding and apologize for any inconvenience this may cause.” Maybe the new motors are better? I was unfortunate and got the one they’ve replaced. So know that at least in my experience I got an inferior machine that died not too long outside of the warranty period and there’s not much the company is willing to do to address that. I’ll look at a better machine for a replacement.
S**A
Poor Quality
The rock Tumbler worked for seven days. Unfortunately the item was a gift for our daughter and had been put away for a month or so resulting in the sellers inability to provide replacement or warranty. I do not recommend this product
D**E
Love it
Thanks so much
J**A
Buen producto
Muy bien producto hasta ahora me a encantado
M**.
Cool product, bad motor
My some was excited to use this but it didn’t last 1 month before breaking down.
N**R
Wrong power cord
I can not use this product as the power cord supplied was for the USA rather than Australia
Trustpilot
1 day ago
2 weeks ago