

💎 Turn Rough Rocks into Polished Perfection — Quietly, Precisely, Effortlessly!
The KoolStone C1 Rock Tumbler Kit is a professional-grade, large-capacity (2.5LB) rock tumbler designed for beginners and hobbyists. Featuring a noise-reducing rubber barrel that’s 75% quieter than plastic alternatives, it offers adjustable 3-speed controls and a 9-day timer with memory for precise tumbling. The all-inclusive kit includes rough stones, polishing grits, ceramic media, spare belts, and a comprehensive tutorial, supported by a 1-year warranty and 90-day money-back guarantee—making it the perfect STEM-focused gift for millennial professionals seeking a creative, hands-on hobby with family or friends.










| ASIN | B09YM33DGD |
| Age Range Description | Suitable for children aged 13 and above |
| Best Sellers Rank | #9,955 in Toys & Games ( See Top 100 in Toys & Games ) #3 in Kids' Rock Tumblers |
| Brand Name | KoolStone |
| Color | Brush Edition: C1 |
| Customer Reviews | 4.5 out of 5 stars 2,682 Reviews |
| Educational Objective | STEM |
| Included Components | 1-Year Warranty Card, Illustrated Learning Booklet, 1A Power Adapter, Jewelry Fastenings, Mesh Strainer, Screwdriver, 1LB Assorted Rough Rocks, 3 Belts for Spare Use, 4 Bags of Polishing Grits, 1 Bottle Ceramic Tumbling Media, Rock Tumbler Base, 2.5LB Capacity Rubber Barrel |
| Item Dimensions | 11.22 x 9.02 x 5.71 inches |
| Item Type Name | Rock Tumbler |
| Item Weight | 2.84 Kilograms |
| Manufacturer | KoolStone |
| Manufacturer Maximum Age (MONTHS) | 1188.0 |
| Manufacturer Minimum Age (MONTHS) | 156.0 |
| Material Type | 1.)Tyre grade rubber barrel and top-quality stainless steel. 2.) If you received the package and missing parts or damaged, no worries, please feel free to reach out at: [email protected] to take the replacement. 3.) Any problems before purchasing, please reach out at: [email protected] to get the answer. |
| Number of Batteries | 1 AA batteries required. |
| Number of Players | 1 |
| Operation Mode | Manual |
| Power Source | AC Adapter |
| Size | Large |
| Supported Battery Types | No batteries required |
| Theme | Perfect gift for rock lovers and hobbyists to create stunning polished stones. |
| Unit Count | 1 Count |
T**D
Great Tumbler! But do some research about proper tumbling technique before using.
Edit 11/29/23. Still love this tumbler. Had a problem with it. Contacted customer service and they took care of it right away. Awesome company, and the best service! Makes a terrific gift for the holidays. We got one for our grandkids this year. Got this tumbler for Christmas. Favorite gift this year. I Love going out and Beaching and finding Afates, Jasper and Quartz treasures. This unit is great! It's quiet, works well and the company has responsive customer service. It comes with a beautiful color instruction manual. The manual isn't bad. But I've learned from groups that tumble on Facebook and forums that there are several things tumbler manufactures get wrong in the instructions. The biggest one is speed. This tumbler spins too fast in all speeds and will bruise stones easily if you run it in speed 3 or 2. So always run it on speed 1. The manual lists RPMs at the axle I timed the RPMs of the barrel and that is rotating at 70-90. It is still faster than recommended but if you fill the barrel as close to 3/4 as possible along with ceramic filler you can minimize bruising. I included picks from my 2nd Tumble and they turned out good with speed 1 and mostly full tumbler. After first cycle you will need to have filler for other 3 cycles. Ceramic works but if you don't have enough ceramic to fill close to 3/4 I found decorative glass beads at the dollar store that work great as filler. I also use 2 tbs of Borax between each cycle and run for 2 hrs will clean the grit from rocks and tumbler pretty well which is essential por good polish. After polish cycle I run for 2 hrs with 2 tbs Ivory soap flakes to help increase shine. Also be careful in cycle one with small stone as this tumbler turns very fast and small stones can dissappear if you run it for a full week. So I check after 4 days to see if I should pull them out and sub in glass beads as filler. Some stones make take more than a week in first cycle. Agates take awhile and you don't wants pits or irregularities to carry grit into polish cycle. So I try to get very smooth in first stage. Anyways this tumbler is alot of fun and I am looking to purchase other tumblers now. I am particularly interested in a vibratory tumbler, they are much faster and use less grit. Potentially you can have polished rocks in a week instead of a month.
M**R
Great value for people who constantly tumble rocks.
Product works well. Arrived with extra belts, some stones, grit, and ceramic. Customer service A+. MOTOR died two weeks into tumbling; I contacted customer support and messaged with Daisy. She sent out a replacement motor which I received within a week. Also sent out a screw driver and extra screws, and emailed a link to a video to show how to take out the old motor and replace it. Replacement was easy. Machine is up and tumbling again! Barrel size is larger than my other tumbling barrels. Noise level isn't quiet, but it isn't outrageous either. It is compact, light weight, and for the money, it is an excellent product. The bonus is the customer service.
K**N
Great rock tumbler for beginners or anyone looking for a quiet tumbler!
Very pleased with this tumbler, I am a beginner at tumbling and rock collecting for the most part, i love the easiness of set up and instructions, comes with multiple pendants/jewelry for making them. Also comes with 2 each pack of grits for each stage. May take about a month but I am so pleased with this item! The sound quality is very great as well, very quiet in my opinion, can’t hear it in the room against the garage either and it’s right against that wall! You really only hear it if you’re RIGHT out in the garage. For people who don’t mind a little noise it’s a great clicking noise I’m sure some people could even fall asleep to lol, it’s that quiet! The rubber really helps, the manual is super simple and has every single step especially for a beginner! I got the brushless edition because they are supposed to last longer and have better results I read online! Comes with extra belts, pendants, rock grits, 1lb of rocks (it was 15.4oz so just about a lb a little under but that is besides the point, they are very nice size as well. I love the size of the tumbler as well, it’s very cute. The durability seems great as well and it’s super simple, no mess ups! The speed adjusts as well, but follow the manual for best options on starting! It is very educational as well considering the manual is pretty dummy proof, perfect for beginners or even professionals! Functionality so far is great as well, will keep updated if anything changes. I read they have great customer service as well, so I’m very pleased!
R**E
Works okay but my stones are not shiny
I recently took up "rock hounding", and was excited to polish the rocks I've discovered, as well as the ones included in the kit. Compared to tumblers I've had in the past, this one is quite a bit quieter. The manual is pretty straightforward, and easy to do. I must say that after following the process to the letter, the end results were a bit disappointing. I am a fan of crystals and, minerals, and use them for many things. Compared to the rocks that I have purchased, the ones that I tumbled just don't have a high shine to them. I even soaked them in mineral oil for a few days, hoping they would achieve the luster that I was looking for. I will continue to use the tumbler, and hopefully I will get better results in the future. UPDATE: The seller reached out to me offering a refund, and gave me a tip on how to use Borax to get shiny stones. I declined the refund, and I ran the stones through the Borax as instructed. Still no shine at all, I am including a picture of my last batch. Update: the seller has reached out to me repeatedly to make sure that I am completely satisfied. I have rarely seen such dedication from a company towards it's customers, and I am highly impressed! They are currently working on a better polish, and have even offered to send me some to use on my dull batches, once it has been perfected. I have added another star due to absolutely outstanding customer support from this company.
K**.
Great product and amazing customer service!
Love the tumbler! Been using it for almost a year. Obviously loud because of the rocks tumbling! The belts do break which is understandable and completely normal. Support was wonderful in getting me some more. I used it for a full year before needing replacements. Its been a lot of trial and error but love how the rocks turn out and im looking forward to giving family members necklaces that have the polished rocks in them. The stones I picked are all from a place thats important to us so it will mean a lot for them to be able to have that piece of the cabin to carry with them. Great gift and super fun to see how the rocks turn out!
M**N
Tumbling into Valentine's Day 💌
I purchased for my 7yr old son for Christmas. He has a true love for rocks, minerals, crystals & seashells. This has been so much fun to do with him. This machine is hardy & it works awesome. Simple step directions, a little on noisy side, so we run when gone for the day. Very nice starter kit. Rocks and glass come out a lot different to how they go in! Today's special surprise was the glass heart ❤️
S**T
Quality and Amazing Customer Care
Easy to use. Easy to understand instructions. I had an issue with the motor not working. Daisy, the customer service rep extraordinaire, send another motor within a few days, and I easily swapped it. They offer a 1-year warranty on everything. The quality of the unit is very good. I will purchase more from this seller without hesitation.
J**S
Perfect for anyone even first time users.
It has very good instructions for first time users. Everything you need for learning is in the box. It works amazing! It is quieter than the early ones. Very happy with this purchase.
Trustpilot
2 months ago
2 days ago