---
product_id: 442292850
title: "C1 Rock Tumbler Kit - 2.5LB Rotary Rock Tumbler for Adults & Hobbyists, Quiet Rubber Barrel, Adjustable Timer & 3 Speeds, Complete Gem Polishing Kit with Memory Function"
brand: "koolstone"
price: "$199.85"
currency: USD
in_stock: true
reviews_count: 13
category: "Kool Stone"
url: https://www.desertcart.us/products/442292850-c1-rock-tumbler-kit-2-5lb-rotary-rock-tumbler-adults
store_origin: US
region: United States of America
---

# 75% quieter rubber barrel design 9-day adjustable digital timer with memory 2.5 lb large rubber barrel capacity C1 Rock Tumbler Kit - 2.5LB Rotary Rock Tumbler for Adults & Hobbyists, Quiet Rubber Barrel, Adjustable Timer & 3 Speeds, Complete Gem Polishing Kit with Memory Function

**Brand:** koolstone
**Price:** $199.85
**Availability:** ✅ In Stock

## Summary

> 💎 Turn rough rocks into polished treasures — your gem journey starts here!

## Quick Answers

- **What is this?** C1 Rock Tumbler Kit - 2.5LB Rotary Rock Tumbler for Adults & Hobbyists, Quiet Rubber Barrel, Adjustable Timer & 3 Speeds, Complete Gem Polishing Kit with Memory Function by koolstone
- **How much does it cost?** $199.85 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/442292850-c1-rock-tumbler-kit-2-5lb-rotary-rock-tumbler-adults)

## Best For

- koolstone enthusiasts

## Why This Product

- Trusted koolstone brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Trusted & Supported:** Join over 1 million KoolStone users backed by responsive customer service, 3 spare belts, and a 1-year warranty for worry-free polishing.
- • **Complete Starter Kit:** Includes 1 lb rough stones, 4 polishing grits, ceramic media, jewelry findings, and a step-by-step guide to launch your gem-polishing journey.
- • **Smart Timer with Memory:** Customize your 9-day polishing cycle with 3 speeds, pause/resume anytime, and never lose settings after power interruptions.
- • **Perfect for STEM & Hobbyists:** Designed for adults and beginners alike, this kit blends science, creativity, and craftsmanship into a rewarding hands-on hobby.
- • **Polish More, Quieter & Cleaner:** Spacious 2.5 lb rubber barrel cushions stones and cuts noise by 75% for a premium tumbling experience at home or workshop.

## Overview

The KoolStone C1 Rock Tumbler Kit is a professional-grade, quiet rotary tumbler with a large 2.5 lb rubber barrel, adjustable 9-day digital timer with memory, and 3 speed settings. Designed for adults and hobbyists, it includes all essential supplies—rough stones, polishing grits, ceramic media, and jewelry findings—plus detailed instructions. Its noise-reducing barrel and smart controls make it ideal for home use, while the 1-year warranty and customer support ensure a confident start to your rock-polishing hobby.

## Description

desertcart.com: KoolStone C1 Rock Tumbler Kit - 2.5LB Rotary Rock Tumbler for Adults & Hobbyists, Quiet Rubber Barrel, Adjustable Timer & 3 Speeds, Complete Gem Polishing Kit with Memory Function : Toys & Games

Review: 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.
Review: Works great - Great little rock tumbler. My 7 year old has had so much fun tumbling rocks with this. It does a great job and I have no complaints. Booklets include gives good instruction, settings are easy, lid is easy to come in and off if you follow directions. Doesn’t come with enough tumbling powder but I ordered more knowing I would have to

## Features

- Designed for Adults and Beginner Hobbyists – Turn rough rocks into polished gemstones with an easy-to-follow home tumbling system. The complete kit, simple controls and step-by-step guide make it easier to start your first batch while still offering enough capacity for an ongoing rock-polishing hobby.
- Large 2.5 lb Capacity with a Quieter Rubber Barrel – Polish more stones in each batch with a spacious 2.5 lb barrel—a practical step up from smaller 1 lb starter tumblers. Its thick rubber construction helps cushion rock impact and produces up to 75% less noise than typical plastic barrels for a more comfortable tumbling experience in garages, workshops and hobby spaces.
- Smart Controls with Pause, Resume and Memory – Choose from 3 speed settings and program each polishing stage with the clear 9-day digital timer. Pause the tumbler to check your rocks, then resume the batch without starting over. Automatic shutoff stops operation when the selected time ends, while the memory function restores your previous settings after a power interruption.
- Complete Kit for Your First Tumbling Batch – Includes a 2.5 lb rubber barrel, 1 lb of rough gemstones in 9 varieties, 4 polishing grits, ceramic tumbling media, a mesh strainer, jewelry findings, an illustrated step-by-step guide and 3 drive belts. The essential supplies for completing your first polishing journey and turning finished gems into keepsakes are included.
- Clear Guidance from Rough Rocks to Polished Gems – Follow the illustrated guide through each stage of the tumbling process. Each stage generally takes several days, and full results may take a few weeks depending on the rock type, size and desired shine. The tumbler is suitable for agate, jasper, quartz, aventurine, tiger’s eye，sea glass and similar hard stones.
- Replacement Belts and Responsive Customer Support – Three included drive belts help keep future tumbling batches moving, while replaceable components support continued use over time. The KoolStone support team is available to help with setup, operation, troubleshooting and replacement-part questions as you build experience with the hobby.
- Over 1,000,000 KoolStone Rock Tumblers Sold In The U.S. – Trusted by families and hobbyists across the country, KoolStone has helped make rock tumbling more approachable and enjoyable. The C1 combines simple controls, practical capacity and complete supplies to help new users begin tumbling with confidence. Based on internal KoolStone U.S. unit sales data through June 2026.
- Official KoolStone Warranty – 𝟏 𝐘𝐞𝐚𝐫 𝐂𝐨𝐯𝐞𝐫𝐚𝐠𝐞 & 𝟗𝟎-𝐃𝐚𝐲 𝐑𝐢𝐬𝐤-𝐅𝐫𝐞𝐞 𝐓𝐫𝐢𝐚𝐥. Your purchase is protected by KoolStone’s official 𝟏-𝐲𝐞𝐚𝐫 𝐰𝐚𝐫𝐫𝐚𝐧𝐭𝐲 and a 𝟗𝟎-𝐝𝐚𝐲 𝐦𝐨𝐧𝐞𝐲-𝐛𝐚𝐜𝐤 𝐠𝐮𝐚𝐫𝐚𝐧𝐭𝐞𝐞. Shop with confidence — we’re here to support your tumbling journey.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B09YM33DGD |
| Age Range Description | Suitable for children aged 13 and above |
| Best Sellers Rank | #4,733 in Toys & Games ( See Top 100 in Toys & Games ) #2 in Kids' Rock Tumblers |
| Brand Name | KoolStone |
| Color | Brush Edition: C1 |
| Customer Reviews | 4.5 out of 5 stars 2,438 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 |
| Indoor Outdoor Usage | Indoor |
| Item Dimensions | 11.22 x 9.02 x 5.71 inches |
| Item Type Name | Rock Tumbler |
| Item Weight | 2.84 kg |
| Manufacturer | KoolStone |
| Manufacturer Maximum Age (MONTHS) | 1188 |
| Manufacturer Minimum Age (MONTHS) | 156 |
| Manufacturer Part Number | KS20220422 |
| Manufacturer Warranty Description | 1 Year Warranty Against Manufacturer Defects |
| 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: support@ikoolstone.com to take the replacement. 3.) Any problems before purchasing, please reach out at: support@ikoolstone.com to get the answer. |
| Model Number | KS20220422 |
| Number of Batteries | 1 AA batteries required. |
| Number of Players | 1 |
| Operation Mode | Manual |
| Power Source | AC Adapter |
| Set Name | C1 Rock Tumbler Kit |
| 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 |

## Images

![C1 Rock Tumbler Kit - 2.5LB Rotary Rock Tumbler for Adults & Hobbyists, Quiet Rubber Barrel, Adjustable Timer & 3 Speeds, Complete Gem Polishing Kit with Memory Function - Image 1](https://m.media-amazon.com/images/I/81hC+5nU+gL.jpg)

## Available Options

This product comes in different **Style** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Great Tumbler! But do some research about proper tumbling technique before using.
*by T***D on March 12, 2023*

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.

### ⭐⭐⭐⭐⭐ Works great
*by A***Q on July 28, 2026*

Great little rock tumbler. My 7 year old has had so much fun tumbling rocks with this. It does a great job and I have no complaints. Booklets include gives good instruction, settings are easy, lid is easy to come in and off if you follow directions. Doesn’t come with enough tumbling powder but I ordered more knowing I would have to

### ⭐⭐⭐⭐⭐ Great small rock tumbler….
*by A***S on March 30, 2026*

Great product. Works well, tumbles relatively quietly in the rubber drum. Easy to load/unload rocks for the various stages. Easy to set up the duration in days and speed required. Excellent instruction manual. Would recommend to buy for anyone interested in seeing the beauty hidden away in some fairly common rocks..

## Frequently Bought Together

- KoolStone C1 Rock Tumbler Kit - Professional Large 2.5LB Capacity, Up to 5X More Noise Cancelling, Adjustable Timer & Speed with Full Accessories & Memory Function, Ideal for Adults Kids
- 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
- 5 Packs of Rock Tumbler Replacement Belts, Only Compatible with KoolStone C1, C1 Pro & C3 Rock Tumbler, 78 * 4mm

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-08-06*