--- product_id: 243528911 title: "NATIONAL GEOGRAPHIC Hobby Rock Tumbler Kit - Rock Polisher for Kids & Adults, Durable Noise-Reduced Barrel, Rocks, Grit & New GemFoam for a Shiny Finish, Cool Toys, Great STEM Hobby Kit" brand: "blue marble" price: "€ 171.45" currency: EUR in_stock: true reviews_count: 13 category: "Blue Marble" url: https://www.desertcart.hr/products/243528911-national-geographic-hobby-rock-tumbler-kit-rock-polisher-for-kids store_origin: HR region: Croatia --- # Includes 9 gemstone types + GemFoam polisher 75% quieter leak-proof barrel Powerful motor with timer NATIONAL GEOGRAPHIC Hobby Rock Tumbler Kit - Rock Polisher for Kids & Adults, Durable Noise-Reduced Barrel, Rocks, Grit & New GemFoam for a Shiny Finish, Cool Toys, Great STEM Hobby Kit **Brand:** blue marble **Price:** € 171.45 **Availability:** βœ… In Stock ## Summary > πŸ’Ž Transform Rough Rocks into Radiant Gems β€” Your Next-Level STEM Hobby Awaits! ## Quick Answers - **What is this?** NATIONAL GEOGRAPHIC Hobby Rock Tumbler Kit - Rock Polisher for Kids & Adults, Durable Noise-Reduced Barrel, Rocks, Grit & New GemFoam for a Shiny Finish, Cool Toys, Great STEM Hobby Kit by blue marble - **How much does it cost?** € 171.45 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/243528911-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 - β€’ **STEM Meets Style:** Turn raw rocks into wearable art with included necklace, ring, keychain, and earring fastenings. - β€’ **Set & Forget Precision:** Customizable tumbling time with automatic shutoff for perfect polish every time. - β€’ **Built to Inspire & Last:** Durable motor and premium materials designed for years of creative exploration and learning. - β€’ **Whisper-Quiet Operation:** Noise-reduced, leak-proof stainless steel barrel keeps your space peaceful while you create. - β€’ **All-Inclusive Gem Creation:** Comes with 227g of rough stones, 4-stage grit, jewelry fastenings, and innovative GemFoam for dazzling shine. ## Overview The National Geographic Hobby Rock Tumbler Kit is a durable, noise-reduced rock polishing system designed for ages 8 and up. Featuring a powerful motor with adjustable tumbling time and a leak-proof stainless steel barrel, it includes 227 grams of assorted rough stones, 4-stage polishing grit, jewelry fastenings, and the innovative reusable GemFoam polisher to deliver brilliantly shiny gemstones. Perfect for STEM enthusiasts and creative professionals seeking a hands-on geology experience that doubles as stylish wearable art. ## Description Product Description National Geographic Hobby Rock Tumbler Kit aplus content video The National Geographic Hobby Rock Tumbler Kit has all the features and accessories you’ll need to master rock tumbling, start an extraordinary rock collection, and create beautiful jewellery. Includes a durable rock tumbler, 226 grams of rough stones to tumble, grit, jewellery settings, and more! Turn rough rocks into amazing gemstones with the Hobby Rock Tumbler Kit! This rock tumbler kit has all the features and accessories you’ll need to master rock tumbling, start an extraordinary rock collection, and create beautiful jewellery. This high-quality tumbling machine boasts a powerful motor that will last for years; a power-saving automatic shutoff timer; and a noise-reducing, leak-proof barrel. Plus, everything is included to get started: a 226 grams of assorted stones from around the world, 4 stages of polishing media, and jewellery fastenings to you can create your own unique wearables with your tumbled gems. Plus, it also includes GemFoam, the most innovative way to add dazzling shine to your polished stones! This high-quality tumbler allows you to set your tumbling time. When the time expires, your tumbler will automatically shut-off, allowing you to choose the perfect amount of tumble time for each grit stage. Plus, our tumbling barrel dampens sound better than most tumblers out there. The rough rocks provided (226 g) contain nine different gemstones from around the world, and our tumbling grit is labeled by tumbling stage to make the process even easier! Choose your favourite gems and turn them into jewellery with the included necklace, key chain, ring, and two clip-on earring fastenings inside. And don't forget about GemFoam, our exclusive new way to add dazzling shine to your polished rocks! Use GemFoam just like tumbling grit, simply add it to the barrel with your stones and water, then three days later marvel at the shine! GemFoam is reusable too, allowing you to create a truly impressive gemstone collection! We make the highest quality hands-on science toys, and all products are backed by exceptional service. 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: Customer service is brilliant - To be honest it started flashing and being very temperamental after a month , then just wouldn't spin. I contacted customer service and they were absolutely brilliant and are sending me a new machine. I've had another one for years with no problems so they don't all go faulty and if they do rest assured the customer service is amazing. Review: Do YouTube research before using, HOWEVER, nice bit of kit. - There are 3 versions of this, the 'toy', the hobby version (this one) and pro version. The pro has a speed control and bigger drum. One thing I have consistently read is.....ignore the supplied instructions. I looked on YouTube and "Michegan Rocks" does a great set of instructions. Basically, the starter rocks are not quite big enough in volume and supplied grit is nowhere near enough. If you really want this to work, it'll take about 6 to 8 weeks with an additional cleaning step so be prepared to need to order more grit, polishing compound and borax/Ivory soap. That way, you are in better stead to get a high quality shine. If you have the time, this'll work a treat. I'm retired so I've got nothing but time. I have this running right now in an upstairs spare room with the door shut and I can't hear it running too much at all but I'll turn it off at night. Very happy with the build quality. Now it's experimenting time! Good luck and don't expect overnight success. Great bit of kit. Review addendum after stage 1: I've added some pictures of the highlights AFTER my stage 1 tumble. The others are BEFORE. I think the result, so far is pretty good. Couple of things. The rocks provided was small in number and on the small size so some little shards are really small. At the moment I'm really just getting a feeling of it but I have to say, I am really pleased. I've ordered some more stage 1 and 2 grit as after 1 more day, I'll be moving to stage 2. I think more rocks and of harder persuasion will be the real test but results so far are well worth the wait. Great bit of kit. ## Features - Warning:Toy inside. Adult supervision recommended - CREATE YOUR OWN GEMSTONES - Rock tumbling is a hugely popular hobby for kids and adults! This robust rock tumbler makes it fun and easy to turn rough rocks into beautifully polished gemstones, thanks to its simple operation and durable design. - A TUMBLER THAT'S MADE TO LAST - The durable motor has tumbling time control settings so you can set it and forget it. The leak-proof barrel features a stainless-steel lid and is 75% quieter overall than plastic tumbler barrels. - ALL-IN-ONE TUMBLING KIT - This kit has everything you need and then some! You get 227 grams of rough rocks with nine different types of gemstones inside, five jewelry fastenings, tumbler grit, a strainer, and our innovative new GemFoam rock polisher. - USE GEMFOAM FOR DAZZLING RESULTS - This rock tumbler kit stands apart from others thanks to our new, reusable GemFoam rock polisher! Add GemFoam and water to the barrel after your final tumbling stage and your gems will have incredible shine! - SATISFACTION GUARANTEED – The National Geographic STEM series provides kids high-quality educational toys 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 | B086Z6ZB7R | | Age Range Description | 8 years and up | | Age range (description) | 8 years and up | | Battery Description | Not required (mains powered) | | Best Sellers Rank | 6,066 in Toys & Games ( See Top 100 in Toys & Games ) 61 in Educational Science Kits | | Brand | Blue Marble | | Brand Name | Blue Marble | | Country Of Origin | China | | Customer Reviews | 4.2 out of 5 stars 5,830 Reviews | | Educational Objective | Geology and Creative Thinking | | Included Components | 1 Professional Rock Tumbler, 227 grams of rough rocks with nine different types of gemstones inside, 5 jewelry fastenings, 4-stage tumbler grit, Strainer, new GemFoam rock polisher | | Is Assembly Required | No | | Item Dimensions | 33.3 x 12.7 x 20.7 centimetres | | Item Type Name | Hobby Rock Tumbler Kit - Rock Polisher for Kids & Adults | | Item Weight | 1.9 Kilograms | | Item dimensions L x W x H | 33.3 x 12.7 x 20.7 centimetres | | Item weight | 1.9 Kilograms | | Language | English | | Manufacturer | JMW Sales, Inc. | | Manufacturer Part Number | NGHOBBYTUMBLER2 | | Manufacturer Warranty Description | No Warranty | | Material Type | default_no_selection_value | | Maximum Age Recommendation | 120 | | Minimum Age Recommendation | 96.00 | | Model Number | NGHOBBYTUMBLER2 | | Set Name | Hobby Rock Tumbler Kit | | Size | 13.86 x 5.04 x 8.15 inches | | Sub Brand | National Geographic | | Theme | Geology | | UPC | 816448028830 | | Unit Count | 1.0 count | ## Product Details - **Age range (description):** 8 years and up - **Brand:** Blue Marble - **Item dimensions L x W x H:** 33.3 x 12.7 x 20.7 centimetres - **Size:** 13.86 x 5.04 x 8.15 inches - **Theme:** Geology ## Images ![NATIONAL GEOGRAPHIC Hobby Rock Tumbler Kit - Rock Polisher for Kids & Adults, Durable Noise-Reduced Barrel, Rocks, Grit & New GemFoam for a Shiny Finish, Cool Toys, Great STEM Hobby Kit - Image 1](https://m.media-amazon.com/images/I/81540OkRB7L.jpg) ## Available Options This product comes in different **Style** options. ## Questions & Answers **Q: What is the power consumption of this unit over a week of continuous use? (in usa on 110v). thank you.** A: This takes .3 Amps, so (watts = amps x volts) OR watts = .3 x 110 which equals33 watts. Now for one week would equal 33 watts x 7 days x 24 hours =5544 watts or 5.54 kilowatts for one week.At $.16 per kilowatt it comes to $.89 per week. **Q: What the difference between this and the starter kit?** A: There are two main differences:The Hobby Rock Tumbler has a rubber tumbling barrel with a stainless steel cap, which reduces noise and is more durable. The Starter Kit Rock Tumbler has a plastic barrel. The Hobby Rock Tumbler also has a keypad for setting the number of days you would like it to tumble, where as the Starter Kit Rock Tumbler's setting options are on/off. Thank you for your inquiry. **Q: What pound tumbler is this product?** A: Dearest National Geographic.... why would you only send 1# of rocks with a two pound tumbler? **Q: Can i buy extra grit without the rocks. we have many rocks from "mining" gemstones that i would love to polish. what do you recommend?** A: I recommend you follow the rock tumbler hobbiest MIchigan Rocks on Youtube. He's a good wealth of information for anyone getting into rock tumblers. He and other's mention that the polish from National Geographic is not good. I would go with rock tumbler polish offered by Polly Plastics. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Customer service is brilliant *by V***. on 18 September 2023* To be honest it started flashing and being very temperamental after a month , then just wouldn't spin. I contacted customer service and they were absolutely brilliant and are sending me a new machine. I've had another one for years with no problems so they don't all go faulty and if they do rest assured the customer service is amazing. ### ⭐⭐⭐⭐⭐ Do YouTube research before using, HOWEVER, nice bit of kit. *by M***R on 23 November 2024* There are 3 versions of this, the 'toy', the hobby version (this one) and pro version. The pro has a speed control and bigger drum. One thing I have consistently read is.....ignore the supplied instructions. I looked on YouTube and "Michegan Rocks" does a great set of instructions. Basically, the starter rocks are not quite big enough in volume and supplied grit is nowhere near enough. If you really want this to work, it'll take about 6 to 8 weeks with an additional cleaning step so be prepared to need to order more grit, polishing compound and borax/Ivory soap. That way, you are in better stead to get a high quality shine. If you have the time, this'll work a treat. I'm retired so I've got nothing but time. I have this running right now in an upstairs spare room with the door shut and I can't hear it running too much at all but I'll turn it off at night. Very happy with the build quality. Now it's experimenting time! Good luck and don't expect overnight success. Great bit of kit. Review addendum after stage 1: I've added some pictures of the highlights AFTER my stage 1 tumble. The others are BEFORE. I think the result, so far is pretty good. Couple of things. The rocks provided was small in number and on the small size so some little shards are really small. At the moment I'm really just getting a feeling of it but I have to say, I am really pleased. I've ordered some more stage 1 and 2 grit as after 1 more day, I'll be moving to stage 2. I think more rocks and of harder persuasion will be the real test but results so far are well worth the wait. Great bit of kit. ### ⭐⭐⭐⭐ Good product but very noisy *by W***S on 1 February 2021* The product works but be aware that it needs to stay on 24 hours a day for 3 to 4 weeks to complete a cycle and it is noisy so if you don’t have a room far away with a socket I would not recommend it. On the other hand I must say it does work and the stones look great. ## Frequently Bought Together - NATIONAL GEOGRAPHIC Hobby Rock Tumbler Kit – Durable Leak-Proof Rock Polisher with 7-Day Timer – Complete Rock Tumbling Kit – Geology Hobby for Kids, Educational STEM Science Kit, Rock Collection - 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 Refill Kit – 1Lb. Gemstones and Rocks for Tumbling including Unpolished Amethyst and Quartz – Rock Tumbler Supplies include Rock Tumbler Grit and Jewelry Accessories --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hr/products/243528911-national-geographic-hobby-rock-tumbler-kit-rock-polisher-for-kids](https://www.desertcart.hr/products/243528911-national-geographic-hobby-rock-tumbler-kit-rock-polisher-for-kids) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-08-12*