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Ceramic media for rock tumbling is the cheapest upgrade most tumblers never make. It solves the most common problem in small batches, an underfilled barrel, and it cushions fragile stones, carries grit into pits and crevices, and helps flat pieces roll instead of slide.
The choices are simpler than the listings suggest. You need the right size for your stones and barrel, a non-abrasive product (not metal-deburring media), and enough weight to top up your barrel batch after batch. Plastic pellets are the alternative for cushioning in the final stages. Every size and weight below comes from the seller's listing.
Quick Picks
- Best Overall: GANGOU 8 LB Ceramic Filler Media, 3/16 x 3/8 in. Best for the standard small cylinder in a bulk bucket.
- Best for Kit Tumblers: National Geographic Ceramic Media 1.5 Lb. Refill. Best for 1 to 3 lb kit barrels.
- Best Mixed Sizes: YHAspace Mixed-Size Ceramic Media 2 LB. Best for three cylinder sizes in one bag.
- Best Small Media: GANGOU 4 Pound Ceramic Media, 1/8 x 1/4 in. Best for cushioning obsidian, quartz and glass.
- Best for Large Barrels: YHAspace 8 LBS Ceramic Media, 1/4 x 1/2 in. Best for 6 lb to 15 lb barrels.
- Best Grit and Media Combo: KomeStone 4LB Grit Kit with Ceramic Media. Best for a full four-step grit set with media in one order.
- Best Plastic Pellets: Roly Poly Plastic Pellets 3 LBS. Best for cushioning in polish and burnish stages.
Ceramic Media Comparison Table
| Product | Best for | Type | Size | Pack weight | Notes from the listing |
|---|---|---|---|---|---|
| GANGOU 8 LB | Overall | Ceramic cut cylinders | 3/16 x 3/8 in | 8 lb | Non-abrasive; packed in a plastic bucket |
| NatGeo Ceramic Media | Kit tumblers | Ceramic pellets | Not stated | 1.5 lb | Reusable in every grit cycle |
| YHAspace Mixed-Size | Mixed sizes | Ceramic cylinders | 1/8 x 1/4, 3/16 x 3/8, 5/16 x 5/8 in | 2 lb | Three sizes in one bag |
| GANGOU 4 Pound | Small media | Ceramic cylinders | 1/8 x 1/4 in | 4 lb | Non-abrasive |
| YHAspace 8 LBS | Large barrels | Ceramic cylinders | 1/4 x 1/2 in | 8 lb | Non-abrasive |
| KomeStone 4LB Grit Kit | Combo | Grit kit plus ceramic | Not stated | 4 lb of grit and media in total | Rated for up to 25 lb of rock |
| Roly Poly 3 LBS | Plastic pellets | Plastic | Not stated | 3 lb | Floats; made in USA from virgin material |
The Best Ceramic Media, Reviewed
GANGOU 8 LB Rock Tumbling Ceramic Filler Media 3/16 x 3/8: Best Overall
Who it's for: anyone running regular batches in 2 to 12 lb barrels.
The 3/16 x 3/8 inch cut cylinder is the hobby's workhorse size. It's the same size Rocktumbler.com sells as its "small" ceramic and recommends as a source of small material in any batch. GANGOU's 8 lb pack comes in a sturdy plastic bucket, which matters more than it sounds: you'll be rinsing, drying and storing media between every stage.
GANGOU describes it as non-abrasive and reusable through every grit cycle. Eight pounds is enough to top up a 3 lb barrel for many batches, or to give a 12 lb barrel a proper media share. GANGOU also sells the same cylinder in 2 lb and 4 lb packs if you want to start smaller.
Pros
- Standard 3/16 x 3/8 in size suits most barrels
- 8 lb lasts many batches
- Bucket for storage between stages
- Smaller pack sizes available
Cons
- One size only; add larger media for big barrels
- No brand-name pedigree
- Needs breaking in before the polish stage
GANGOU 8 LB Rock Tumbling Ceramic Filler Media 3/16 x 3/8
by GANGOU
National Geographic Ceramic Media for Rock Tumbling 1.5 Lb. Refill: Best for Kit Tumblers
Who it's for: owners of National Geographic, KomeStone, KoolStone and other 1 to 3 lb kit tumblers.
Kit barrels are where media makes the biggest difference. Most kits ship 1/2 to 1 lb of rough, which leaves a 2 lb barrel badly underfilled. National Geographic's 1.5 lb refill is sized for exactly that gap.
National Geographic says the media improves grit delivery, quiets tumbler noise, reduces rock breakage and acts as filler for smaller batches. It's reusable in every grit cycle, and the brand suggests using worn pellets in place of smaller media as they shrink. It works in any tumbler.
The listing doesn't state the pellet size, so you can't match it precisely to other media.
Pros
- Right quantity for small kit barrels
- Reusable through every stage
- Works in any brand of tumbler
- Easy add-on to a National Geographic refill order
Cons
- Pellet size not published
- Higher cost per pound than bulk packs
- Too little for big barrels
National Geographic Ceramic Media for Rock Tumbling 1.5 Lb. Refill
by National Geographic
YHAspace Mixed-Size Rock Tumbling Ceramic Filler Media 2 LB: Best Mixed Sizes
Who it's for: tumblers who want the mixed-size load that experienced hobbyists recommend, without buying three bags.
Rocktumbler.com recommends a mix of small and large media for new users. A range of sizes creates more contact points, which speeds shaping and reduces chipping, and the cylinders act like roller bearings for flat or angular pieces.
YHAspace packs three cylinder sizes into one 2 lb bag: 1/8 x 1/4 in (small), 3/16 x 3/8 in (medium) and 5/16 x 5/8 in (large). That covers crevices, general filling and big-stone support in one purchase. Two pounds suits 3 to 6 lb barrels.
Pros
- Three sizes in one bag
- Matches the mixed-size approach Rocktumbler.com recommends
- Good for slabs and flat pieces
- Reusable
Cons
- Only 2 lb
- You can't choose the ratio of sizes
- Small pieces are harder to separate from small stones
YHAspace Mixed-Size Rock Tumbling Ceramic Filler Media 2 LB
by YHAspace
GANGOU 4 Pound Rock Tumbling Ceramic Filler Media 1/8 x 1/4: Best Small Media
Who it's for: anyone tumbling fragile, bruise-prone material such as obsidian, crystalline quartz, feldspars or glass.
Small media cushions best. Rocktumbler.com says it runs at least 50% media in the barrel for especially fragile rough, and that a large share of small media significantly reduces bruising in obsidian and crystalline quartz. It also says small media in the fine and polish stages can brighten the polish.
GANGOU's 1/8 x 1/4 inch cylinders are smaller than the standard 3/16 x 3/8 inch size, and the 4 lb pack is enough for a high media ratio in a 3 lb barrel. It's also the size to reach for when you make sea glass in a rock tumbler.
Pros
- Small size cushions fragile stones best
- 4 lb supports a 50% media ratio
- Gets into pits and crevices
- Helps the polish stage
Cons
- Wears down faster than large media
- Harder to separate from small stones
- Too small to help large stones tumble
GANGOU 4 Pound Rock Tumbling Ceramic Filler Media 1/8 x 1/4
by GANGOU
YHAspace 8 LBS 1/4 x 1/2 Rock Tumbling Ceramic Filler Media: Best for Large Barrels
Who it's for: owners of 6 lb, 12 lb and 15 lb barrels, and anyone tumbling 1-1/2 inch and bigger stones.
Big barrels need bigger media. Small cylinders get lost among 2 to 3 inch stones, and large stones can crush each other if there isn't enough material between them. Rocktumbler.com's beach-cobble tests used lots of small media plus around 20% to 30% total media to keep large rocks from crushing each other.
YHAspace's 1/4 x 1/2 inch cylinders sit between standard small and large media, and 8 lb is a realistic quantity for a 12 lb barrel. Rocktumbler.com notes that larger media lasts much longer and eventually wears down to small media, so a big bag keeps paying off. Our upcoming guide to large rock tumblers covers the machines it suits.
Pros
- Larger size supports big stones
- 8 lb suits big barrels
- Long-lasting
- Wears into smaller media over time
Cons
- Too large to cushion small, fragile stones
- Heavy to store
- Mix with small media for best results
YHAspace 8 LBS 1/4 x 1/2 Rock Tumbling Ceramic Filler Media
by YHAspace
KomeStone Rock Tumbler Grit Kit 4LB with Ceramic Tumbling Media: Best Grit and Media Combo
Who it's for: small-barrel owners who want a complete grit set with media in one order.
We first picked a 4 lb KoolStone grit-and-media kit here, but we couldn't find it on Amazon.com when we checked in October 2026. KomeStone's 4LB kit is the closest match we could confirm. Its listing describes 4 lb of polishing grit and ceramic tumbling media for a four-step process, rated to polish up to 25 lb of rock, and says it works with any rock tumbler or polisher.
Buying grit and media together saves a separate order. Our check of the listing didn't confirm how the 4 lb splits between grit and media, so look at the bag sizes before you buy. For dosing, Rocktumbler.com's rule of about 2 tablespoons of grit per pound of rock is a sound starting point. If you run batches often, the 10 lb KoolStone kit in our rock tumbler grit guide works out cheaper per pound.
Pros
- Four-step grit set and ceramic media in one order
- Rated for up to 25 lb of rock
- Works in any brand of tumbler, per KomeStone
Cons
- The split between grit and media isn't confirmed here
- Media size not stated
- Bulk media is cheaper per pound
KomeStone Rock Tumbler Grit Kit 4LB with Ceramic Tumbling Media
by KomeStone
Roly Poly Plastic Pellets Rock Tumbling Media 3 LBS: Best Plastic Pellets
Who it's for: rotary tumblers who want cushioning in the pre-polish, polish and burnish stages.
Plastic pellets do a different job from ceramic. They're light and soft, so they cushion stones but do little grinding. Kingsley North's rotary instructions use plastic pellets to bring the barrel up to 2/3 to 3/4 full in the later stages, where fresh chips on nearly finished stones would be a disaster.
Roly Poly's 3 lb bag is made in the USA from virgin material, according to the listing, and the pellets float, which makes them easy to skim off during rinsing. It comes in a resealable heavy-duty bag.
Use them carefully. Rocktumbler.com says grit embeds in plastic, so pellets should stay with one grit size. Label a separate bag for each stage. It also says plastic isn't a good filler and isn't recommended for vibratory tumblers.
Pros
- Excellent cushioning in late stages
- Floats, so it's easy to separate
- Resealable bag for storage
- Made in USA, per the listing
Cons
- Can't move between grit sizes
- Doesn't help grinding
- Not for vibratory tumblers
Roly Poly Plastic Pellets Rock Tumbling Media 3 LBS
by Roly Poly
Buying Guide: How to Choose Rock Tumbling Media
What Media Actually Does
Media earns its place in four ways, according to Rocktumbler.com's media guide:
- Filler. Coarse grit removes roughly 10% to 30% of the rock's volume. Media replaces it so the barrel stays near the recommended two-thirds full. Lortone recommends filling 1/2 to 2/3; Kingsley North and Harbor Freight allow up to 3/4.
- Cushioning. Media reduces how often and how hard stones hit each other, which cuts bruises and chips.
- Grit delivery. Small media carries grit into pits, crevices and concave surfaces that stones can't reach.
- Tumbling action. Cylinders act like roller bearings so slabs and angular pieces tumble instead of sliding.
How Much Media to Use, Stage by Stage
| Situation | Media share (by volume) | Source |
|---|---|---|
| Coarse stage, durable stones (agate, jasper) | None to about 10% | Rocktumbler.com |
| Coarse stage, general rule | About 10%, up to about 20% | Rocktumbler.com |
| Medium stage | Enough to reach about 2/3 full | Rocktumbler.com |
| Fragile stones (obsidian, crystalline quartz, glass) | At least 50% | Rocktumbler.com |
| Pre-polish and polish (plastic pellets) | Bring barrel to 2/3 to 3/4 full | Kingsley North |
| Glass | 3 to 4 heaping Tbsp ceramic per lb of glass | Rocktumbler.com |
KomeStone, for its part, tells kit owners to keep its ceramic media in for all stages. That's fine as long as you wash it thoroughly between stages.
Hardness matters here too. Softer stones (below about Mohs 6) wear and bruise faster, so they benefit from more media. Our guide to the best rocks for tumbling groups stones by hardness.
Size: Mix Small and Large
- Small (1/8 x 1/4 to 3/16 x 3/8 in): best cushioning, best at reaching crevices, helps the polish. Wears down faster.
- Large (1/4 x 1/2 to 3/8 x 5/8 in): fills volume, supports big stones, lasts many cycles.
- Mixed: what Rocktumbler.com recommends for new users. Large media gradually wears into small media, so a mixed supply refreshes itself.
Ceramic vs Plastic Pellets
| Ceramic | Plastic pellets | |
|---|---|---|
| Hardness | About Mohs 7+, per Rocktumbler.com | Soft |
| Helps grinding | Yes | Little |
| Stages | All, if washed well | One grit size only |
| Cleaning | Rinses clean easily | Hard to clean; floats |
| Vibratory tumblers | Yes | Not recommended, per Rocktumbler.com |
| Best use | Filler, cushioning, grit delivery | Cushioning in polish and burnish |
Rocktumbler.com says it sells more than 10 times as much ceramic media as plastic by weight, which tells you where the hobby has gone.
Avoid Abrasive "Fast-Cut" Media
Many ceramic media listings are made for metal deburring, with triangles and angle-cut shapes described as fast-cutting or aggressive. That's the opposite of what you want for stones. Rocktumbler.com warns that ceramic media with embedded abrasive granules will scratch stones and ruin the polish. Buy media described as non-abrasive filler for rock tumbling.
Break In New Media
New ceramic media has sharp edges and a rough surface. Rocktumbler.com says it's fine in coarse and medium stages, where it smooths itself, but shouldn't go straight into fine or polish. Either use media that has already been through earlier stages, or run new media a few days in medium grit and a few in fine before using it in polish.
Keep Media Clean Between Stages
Wash media as carefully as your stones. Media that carries coarse grit into the polish will scratch every stone. Store media from the polish stage separately from coarse-stage media. If your stones still come out dull, our upcoming rock tumbler troubleshooting guide covers contamination. For the full process, see our how to rock tumble guide.
How We Chose
We didn't tumble with these media ourselves. We researched them. We compared listed sizes, weights and materials against Rocktumbler.com's media guidance and the fill-level instructions in Lortone's, Kingsley North's and Harbor Freight's manuals. We favored products described as non-abrasive filler for rock tumbling, chose a range of sizes for different barrels, and left out metal-deburring media and listings with no current offers.
FAQ
Do you need ceramic media for rock tumbling?
Not always, but it helps in most batches. Media fills the barrel to the recommended level, cushions stones, and carries grit into crevices. Rocktumbler.com says coarse grit removes roughly 10% to 30% of the rock's volume, and media replaces that loss so the barrel stays near two-thirds full.
How much ceramic media should I use?
In the coarse stage, about 10% media by volume, per Rocktumbler.com, and up to about 20% in some cases. For durable agate and jasper, use little or none in coarse. For fragile stones such as obsidian or crystalline quartz, Rocktumbler.com uses at least 50% media.
What size ceramic media is best?
A mix of sizes. Rocktumbler.com recommends combining small and large media, such as 3/16 x 3/8 inch and 3/8 x 5/8 inch cylinders. Small media cushions best and reaches crevices; large media lasts longer and helps big stones tumble.
Can you reuse ceramic media?
Yes. Ceramic media is reusable through all stages if you wash it well between stages. Large media lasts many cycles and slowly wears down into small media. Plastic pellets are different: Rocktumbler.com says they should stay with one grit size because grit embeds in them.
Ceramic media or plastic pellets?
Ceramic for most people. It's dense enough to help grinding, easy to rinse clean, and usable in every stage. Plastic pellets are lighter and mainly cushion stones in the pre-polish and polish stages; Kingsley North uses them to bring the barrel to 2/3 to 3/4 full in later stages.
Verdict
For most tumblers, the GANGOU 8 lb bucket of 3/16 x 3/8 inch cylinders is the best ceramic media buy: the standard size, in a quantity that lasts. Add the GANGOU 1/8 x 1/4 inch media if you tumble fragile stones or glass. Kit owners can start with National Geographic's 1.5 lb refill.