---
title: "Rock Tumbler Refill — $46K/yr Amazon US Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/us/industrial-scientific/rock-tumbler-refill"
last_updated: "2026-08-08T08:52:37.952Z"
locale: en
meta:
description: "Niche score 37/100 · $46K/yr market · 19K searches/yr · $26.23 avg price. Doesn't clear our bar today. Data updated Aug 2026."
"og:description": "Niche score 37/100 · $46K/yr market · 19K searches/yr · $26.23 avg price. Doesn't clear our bar today. Data updated Aug 2026."
"og:title": "Rock Tumbler Refill — $46K/yr Amazon US Niche (2026) - Flapen"
---
# **rock tumbler refill**
**Skip it**
Brand-locked demand (top 5 brands take 100% of clicks) — this niche doesn't clear our bar today.
Market size 11Growth 21Conversion 84Competition 12Returns 97Price range 89Avg price 95Brand share 0Review moat 24Quality gap 19
**Returns**
**Incredible****0.7%**
return rate — above 5% kills the launch gate
**Avg price**
**Incredible****$26.23**
avg listing price — sweet spot $15–$100
**Price range**
**Great****$12.64–$41.72**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Conversion**
**Great****9.2%**
search→purchase rate — share of searches ending in a sale
**Review moat**
**Bad****6,231.17**
avg incumbent reviews — the moat a new listing must climb
**Growth**
**Bad****-8.1%**
90-day search growth — must beat 0% to launch
**Quality gap**
**Bad****4.7★**
avg incumbent rating — lower means beatable quality
**Competition**
**Bad****86%**
top-5 click share — a locked-up shelf
**Market size**
**Bad****$46K**
$46K/yr · 19K searches
**Brand share**
**Bad****100%**
top-5 brand share — brand-locked demand
According to Flapen's Amazon United States niche tracking, rock tumbler refill is a $46K/yr Amazon United States market (19K searches/yr). The top 5 brands hold 100% of demand. Demand peaks in Jan–Nov–Dec. Verdict: Skip it — 37/100.
Data updated Aug 6, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **rock tumbler refill market data**
- **Units sold / yr**
- **2K–2K**
- avg 100–250/product
- **Revenue / yr**
- **$39K–$52K**
- units × avg price
- **Conversion rate**
- **9.2%**
- **Avg BSR**
- **#156**
- **Page quality**
- **0%**
- **Prime**
- **100%**
- **Sponsored**
- **92%**
- **Out of stock**
- **0.0%**
- **Avg brand age**
- **69 months**
- **Avg seller age**
- **188 days**
## **Competition & brand share**
The top 5 products capture 86% of clicks — a locked-up shelf that new listings rarely crack.
**Brands**
**5 **▼falling
**Sellers**
**14**
**Top-5 brand share**
**100%**
Top 20: 100%
**Top-5 click share**
**86%**
Top 20: 100%
**Open market**
**0%**
- Blue Marble82% - LARICEO12% - YHAspace3% - Thames & Kosmos2% - WKTURN1%
## **Demand & seasonality**
Weekly Amazon search volume, last 104 weeks — -8.1% search growth over the last 90 days.
2K1KSpike '24Holiday '24Spike '25Prime Day '25Black Friday '25Holiday '25Spike '26 seasonSepDecMarJunAugNovMarMay
Peak months: Jan, Nov, Dec · busiest ÷ quietest = 6.2×
[**Open Trend **](https://flapen.com/research/us/industrial-scientific/rock-tumbler-refill/trend)
## **Top rock tumbler refill search terms**
- **rock tumbler refill kit**7K/yr-13.3%3.5% conv. - **national geographic rock tumbler refill**6K/yr-5.8%11.9% conv. - **rock tumbler refill**6K/yr-3.9%5.2% conv. [**All search terms **](https://flapen.com/research/us/industrial-scientific/rock-tumbler-refill/search-terms)
## **Top rock tumbler refill products on Amazon**
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
0%10%$5K20%$9K30%$14K40%$18K1101001K10K100K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 12 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**NATIONAL GEOGRAPHIC Rock Tumbler Grit and Polish Refill Kit - Tumbling Grit Media Polish Up to 20 lbs. of Rocks Works with any Rock Polisher & Tumbler Supplies**Blue Marble**$23.90**4.7★18,734 rev](https://www.amazon.com/dp/B01MRKI4W0) [2**National Geographic Rock Tumbler Refill Kit with 1 Lb. Gemstone Mix**Blue Marble**$15.09**4.6★6,150 rev](https://www.amazon.com/dp/B017L46G9G) [3**LARICEO Rock Tumbler Grit and Polish Refill Set 4-Step 3 lb**LARICEO**$21.84**4.8★290 rev](https://www.amazon.com/dp/B0DCJDHL6F) [4**NATIONAL GEOGRAPHIC Rock Tumbler Grit & Media Refill Kit Rock Polishing Supplies Kit 4-Stage Silicon Carbide Bulk Grit 1.5 Pounds of Ceramic Pellets Stone Tumbling & GemFoam Polishing Media**Blue Marble**$38.93**4.7★18,734 rev](https://www.amazon.com/dp/B08B7GRBK6) [5**National Geographic Rock Tumbler Refill Kit with 5 Lbs. Rough Rocks**Blue Marble**$35.43**4.6★2,014 rev](https://www.amazon.com/dp/B07XM95HZY)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**The Thames & Kosmos Rock Tumbler Refill Pack for use with The Thames & Kosmos Rock Tumbler Essential STEM Tool for Kids | Includes Rough Rocks Polishing Grit Jewelry Settings**Thames & Kosmos**$12.64**6 rev1y ago](https://www.amazon.com/dp/B0DS6MGHKD) [**LARICEO Rock Tumbler Grit and Polish Refill Set 4-Step 3 lb**LARICEO**$21.84**290 rev1y ago](https://www.amazon.com/dp/B0DCJDHL6F) [**LARICEO Rock Tumbler Grit and Polish Refill Set with Ceramic Media 4.5 lb**LARICEO**$26.14**268 rev2y ago](https://www.amazon.com/dp/B0CKXGSTRM) [**10 Pounds Rock Tumbler Grit Refill - Rock Polishing Grit Media Kit**YHAspace**$32.65**486 rev3y ago](https://www.amazon.com/dp/B0BKW7Y9YW) [**WKTURN Rock Tumbler Grit Set - 4 Step Tumbling Media (Coarse Medium Grit Pre-Polished Final Polish) Set 2.0 for Any Brand of Rock Polisher**WKTURN**$19.29**796 rev4y ago](https://www.amazon.com/dp/B09P15Y11G)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**NATIONAL GEOGRAPHIC Rock Tumbler Grit & Media Refill Kit Rock Polishing Supplies Kit 4-Stage Silicon Carbide Bulk Grit 1.5 Pounds of Ceramic Pellets Stone Tumbling & GemFoam Polishing Media**Blue Marble**$38.93**4.7★**▲ 152%**](https://www.amazon.com/dp/B08B7GRBK6) [**10 Pounds Rock Tumbler Grit Refill - Rock Polishing Grit Media Kit**YHAspace**$32.65**4.7★**▲ 134%**](https://www.amazon.com/dp/B0BKW7Y9YW) [**LARICEO Rock Tumbler Grit and Polish Refill Set 4-Step 3 lb**LARICEO**$21.84**4.8★**▲ 72%**](https://www.amazon.com/dp/B0DCJDHL6F) [**LARICEO Rock Tumbler Grit and Polish Refill Set with Ceramic Media 4.5 lb**LARICEO**$26.14**4.7★**▲ 60%**](https://www.amazon.com/dp/B0CKXGSTRM) [**NATIONAL GEOGRAPHIC Rock Tumbler Grit and Polish Refill Kit - Tumbling Grit Media Polish Up to 20 lbs. of Rocks Works with any Rock Polisher & Tumbler Supplies**Blue Marble**$23.90**4.7★**▲ 12%**](https://www.amazon.com/dp/B01MRKI4W0)
**~~View all trending →~~**
## **What buyers say about rock tumbler refill**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Quality-Overall**20%
*“Good grit”*
**Advertised Vs Actual Product**20%
*“As advertised”*
**Value For Money**18%
*“works good for the money”*
**Efficiency**8%
*“WORKS WELL”*
**Ease Of Use**6%
*“EASY TO USE”*
**Suitability Beginner**5%
*“Good for Beginners”*
**Fun/Entertainment Experience**5%
*“Great fun”*
**Instructions/User Manual/Troubleshooting**4%
*“Easy instructions”*
**Collectibles**2%
*“Beautiful Collection Of Specimens”*
**Correct Contents**2%
*“Perfect amount”*
### **What buyers complain about **
**Size-Overall**19%
*“Smaller than I thought”*
**Quality-Overall**18%
*“Disappointing performance from this product”*
**Functionality-Overall**13%
*“We purchased this and didn't work”*
**Brightness/Shine/Glow**9%
*“No shine to the stones”*
**Advertised Vs Actual Product**6%
*“Very deceptive and will not buy again”*
**Durability**6%
*“Most wont last thru tumbling cycles”*
**Value For Money**6%
*“Not worth the money”*
**Ease Of Use**3%
*“error to use”*
**Leak-Proof**3%
*“sands leaked everywhere”*
### **Top return reasons **
**Advertised Vs Actual Product**21%
**Size-Overall**19%
**Value For Money**11%
**Product Condition**8%
**Functionality-Overall**8%
**Defective Material/Parts**5%
**Leak-Proof**5%
**Quality-Overall**4%
**Gifting Purpose**4%
**Material Quality**3%
## **Common questions**
- **Is rock tumbler refill profitable to sell on Amazon United States?**
- The niche generates $46K/yr across 12 tracked products. 90-day search growth is -8.1%. Flapen's verdict: Skip it (37/100).
- **How competitive is the rock tumbler refill niche?**
- 5 brands and 14 sellers compete. The top 5 products take 86% of clicks and top 5 brands hold 100% of demand.
- **What do buyers complain about in rock tumbler refill?**
- Top complaints mined from reviews: Size-Overall, Quality-Overall, Functionality-Overall. The return rate is 0.7%.
- **When does demand for rock tumbler refill peak?**
- Demand peaks in Jan–Nov–Dec; the busiest month runs 6.2× the quietest.
- **What does it cost to enter the rock tumbler refill niche?**
- Listings span $12.64–$41.72; the average listing price is $26.23 (sweet spot $15–$100). The average incumbent carries 6,231 reviews — the moat a new listing must climb.
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