Best rock tumbler grit & polishing kit (stages explained)

Silicon carbide stages, polish, and ceramic media that finish the job

Rock tumbler grit is the consumable that actually polishes your stones — coarse silicon carbide shapes, finer grits smooth, and aluminum oxide or polish compound brings the shine. We compared complete 4-stage grit kits with ceramic media, bulk refill packs for up to ~20 lb of rock, and media-inclusive kits so you can keep running batches after the starter grit runs out.

Rock Tumbler Grit & Media comparison chart

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ProductPriceStagesBatch sizeMedia includedBest forBuy
Best overallRock Tumbler Grit & Media Refill KitNational Geographic$40 approx.4 + GemFoamUp to ~10 lb rocks1.5 lb ceramic + foamNat Geo & hobby tumblersCheck price on Amazon
Best bulk valueBulk Grit & Polish Refill KitNational Geographic$25 approx.4-stageUp to ~20 lb rocksNoFrequent tumblingCheck price on Amazon
Best with ceramic fillerGrit, Polish & Ceramic Media KitPolly Plastics$32 approx.4-stepUp to ~20 lb rocksCeramic fillerBalanced hobby loadsCheck price on Amazon

Product details

Best overall

National Geographic Rock Tumbler Grit & Media Refill Kit

National Geographic Rock Tumbler Grit & Media Refill Kit
Check price on Amazon

National Geographic’s grit and media pack is the easiest rock tumbler grit refill for hobby machines — four silicon carbide stages, ceramic pellets, and GemFoam polish media in labeled containers.

Features

  • Four-stage silicon carbide grit compound
  • 1.5 lb ceramic tumbling media
  • GemFoam final polish media
  • Scoop and instructions included

Pros and cons

ProsCons
Complete system in one boxPricier per pound than bulk grit
Ceramic media improves resultsOptimized for smaller hobby barrels
Clear stage packaging

Activities and environments best for

  • Beginners restocking kits
  • Nat Geo / similar tumblers
  • Fewer measuring mistakes

Overall

Best all-in-one rock polishing grit kit when you want media and grit together.

Customer reviews

4.7 out of 5

2,200 global ratings

5 star78%
4 star14%
3 star5%
2 star2%
1 star1%
Best bulk value

National Geographic Bulk Grit & Polish Refill Kit

National Geographic Bulk Grit & Polish Refill Kit
Check price on Amazon

National Geographic’s bulk grit refill stretches across many rotary loads — four silicon carbide stages with a scoop, enough to polish roughly 20 lb of rock before you restock.

Features

  • Over 3 lb of 4-stage tumbling grit
  • Wide-mouth screw-top containers
  • 10 mL measuring scoop included
  • Works with any rock tumbler brand

Pros and cons

ProsCons
Strong value per poundNo ceramic media included
Huge review baseYou measure each load
Easy storage jars

Activities and environments best for

  • Weekly hobbyists
  • 3 lb+ barrels
  • Restocking after kit grit runs out

Overall

Best rock tumbler grit buy when kit packets feel tiny.

Customer reviews

4.7 out of 5

14,500 global ratings

5 star78%
4 star14%
3 star5%
2 star2%
1 star1%
Best with ceramic filler

Polly Plastics Grit, Polish & Ceramic Media Kit

Polly Plastics Grit, Polish & Ceramic Media Kit
Check price on Amazon

Polly Plastics pairs 4-step silicon carbide / aluminum oxide grit with ceramic tumbling filler — helpful when your barrel is not full of rock and you want quieter, more even polishing.

Features

  • Coarse through polish stages by weight
  • Ceramic tumbling filler media included
  • Compatible with rotary hobby tumblers
  • USA brand with clear stage guidance

Pros and cons

ProsCons
Media + grit togetherHeavier package
Good review historyStill need to measure loads
Fills partial barrels

Activities and environments best for

  • Partial barrels
  • Agate/jasper batches
  • Noise-conscious setups

Overall

Best when you want ceramic media without buying a separate bag.

Customer reviews

4.7 out of 5

2,700 global ratings

5 star76%
4 star15%
3 star6%
2 star2%
1 star1%
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Rock Tumbler Grit & Media FAQ

What grit do I need for a rock tumbler?

A standard rotary sequence uses four stages: coarse silicon carbide (about 60/90), medium (120/220), fine/pre-polish (400–600), then aluminum oxide or polish compound for the final shine.

Do I need ceramic tumbling media?

Not required, but ceramic pellets help fill small loads, cushion brittle stones, distribute grit, and often quiet the barrel. Kits that include media are worth it for beginners.

How much rock tumbler grit per load?

Follow your grit kit label. Rough rule for rotary: about 1–2 tablespoons of coarse grit per pound of rock, less for finer stages — never mix leftover grit between stages.

Silicon carbide vs aluminum oxide polish?

Silicon carbide does the cutting and smoothing stages. Aluminum oxide (or a dedicated polish) is for the final shine. Do not reuse coarse grit bags for polish stages.

Where should I buy grit if my kit ran out?

A 4-stage rock tumbler grit refill on Amazon is the fastest restock. Match pack size to your barrel (hobby kit vs 3 lb vs bulk) rather than buying industrial drums first.