rock tumbler refill
Skip itBrand-locked demand (top 5 brands take 100% of clicks) — this niche doesn't clear our bar today.
Returns
Incredible0.7%return rate — above 5% kills the launch gate
Avg price
Incredible$26.23avg listing price — sweet spot $15–$100
Price range
Great$12.64–$41.72cheapest to priciest tracked listing — scored on the share inside $15–$100
Conversion
Great9.2%search→purchase rate — share of searches ending in a sale
Review moat
Bad6,231.17avg incumbent reviews — the moat a new listing must climb
Growth
Bad-8.1%90-day search growth — must beat 0% to launch
Quality gap
Bad4.7★avg incumbent rating — lower means beatable quality
Competition
Bad86%top-5 click share — a locked-up shelf
Market size
Bad$46K$46K/yr · 19K searches
Brand share
Bad100%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
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.Peak months: Jan, Nov, Dec · busiest ÷ quietest = 6.2×
Top rock tumbler refill search terms
- rock tumbler refill kit7K/yr
- national geographic rock tumbler refill6K/yr
- rock tumbler refill6K/yr
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.
All 12 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
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$23.904.7★18,734 rev
National Geographic Rock Tumbler Refill Kit with 1 Lb. Gemstone Mix
Blue Marble$15.094.6★6,150 rev
LARICEO Rock Tumbler Grit and Polish Refill Set 4-Step 3 lb
LARICEO$21.844.8★290 rev
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$38.934.7★18,734 rev
National Geographic Rock Tumbler Refill Kit with 5 Lbs. Rough Rocks
Blue Marble$35.434.6★2,014 rev
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$12.646 rev
LARICEO Rock Tumbler Grit and Polish Refill Set 4-Step 3 lb
LARICEO$21.84290 rev
LARICEO Rock Tumbler Grit and Polish Refill Set with Ceramic Media 4.5 lb
LARICEO$26.14268 rev
10 Pounds Rock Tumbler Grit Refill - Rock Polishing Grit Media Kit
YHAspace$32.65486 rev
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$19.29796 rev
Trending
90-day click momentumNATIONAL 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$38.934.7★
10 Pounds Rock Tumbler Grit Refill - Rock Polishing Grit Media Kit
YHAspace$32.654.7★
LARICEO Rock Tumbler Grit and Polish Refill Set 4-Step 3 lb
LARICEO$21.844.8★
LARICEO Rock Tumbler Grit and Polish Refill Set with Ceramic Media 4.5 lb
LARICEO$26.144.7★
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$23.904.7★
What buyers say about rock tumbler refill
What buyers praise and complain about, mined from review topics.What buyers love
“Good grit”
“As advertised”
“works good for the money”
“WORKS WELL”
“EASY TO USE”
“Good for Beginners”
“Great fun”
“Easy instructions”
“Beautiful Collection Of Specimens”
“Perfect amount”
What buyers complain about
“Smaller than I thought”
“Disappointing performance from this product”
“We purchased this and didn't work”
“No shine to the stones”
“Very deceptive and will not buy again”
“Most wont last thru tumbling cycles”
“Not worth the money”
“error to use”
“sands leaked everywhere”
Top return reasons
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.