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A rock polishing compound is the last step that turns a smooth, satin stone into a glassy one. For most tumblers the answer is simple: aluminum oxide works on nearly any agate, jasper or quartz, and it's inexpensive. Cerium oxide is the classic alternative, preferred for feldspars and glass. Tin oxide and chrome oxide fill specialist niches.
Before you buy anything, know this: polish can't fix earlier mistakes. A rushed coarse stage, a short pre-polish or one stray grain of coarse grit will leave stones dull whatever polish you use. Get those right, then choose a compound for your stones and your tumbler.
Quick Picks
- Best Overall: Rocktumbler.com TXP Aluminum Oxide Polish. Best for agate, jasper, quartz and most Mohs 5 to 8 stones.
- Best for Feldspars and Glass: Rocktumbler.com Cerium Oxide Polish. Best for labradorite, moonstone, amazonite, obsidian and glass.
- Best for Vibratory Tumblers: Rocktumbler.com #61 Rapid Polish. Best for an extra-bright finish on fracture-free stones.
- Best Polish in a Grit Set: Lortone 4-Stage Grit Pack. Best for following Lortone's aluminum oxide sequence.
- Best Fine Polish for One Batch: Rockhound's 1st Choice Refill Grit Kit. Best for a 1200 aluminum oxide finish in a single 3 lb batch.
- Best for Rotary Tools: Dremel 421 Polishing Compound. Best paired with Dremel felt wheels.
Rock Polishing Compound Comparison Table
| Polish | Best for | Material | Particle size | Rotary dose | Notes |
|---|---|---|---|---|---|
| TXP | Overall | Aluminum oxide | About 3 microns | About 2 Tbsp per lb of rock plus media | Rocktumbler.com's everyday polish |
| Cerium oxide | Feldspars, glass | Cerium oxide | Not stated | About 2 Tbsp per lb | For Mohs 5 to 8 stones and glass |
| #61 Rapid Polish | Vibratory | Aluminum oxide | About 0.3 microns | Not for rotary | Avoid on fractured or cleavage-prone stones |
| Lortone 4-Stage Pack | Brand kit | Aluminum oxide (pre-polish and polish) | Not stated | 6 Tbsp per 3 lb barrel (3A manual) | 12 oz of polish |
| Rockhound's 1st Choice | One batch | White fused aluminum oxide, 1200 grit | 1.5 microns or finer | Pre-portioned for 3 lb | 1.5 oz of polish |
| Dremel 421 | Rotary tools | Polishing compound | Not stated | n/a | Pairs with Dremel 414 felt |
Particle sizes and doses come from each maker's page; the Lortone dose is from its 3A manual.
The Best Rock Polishing Compounds, Reviewed
Rocktumbler.com TXP Aluminum Oxide Polish: Best Overall
Who it's for: almost everyone tumbling agate, jasper, quartz and petrified wood.
Rocktumbler.com describes aluminum oxide as Al2O3, the same compound as corundum, at Mohs 9, and says it costs less than half as much as cerium or tin oxide. Its TXP polish centers around 3 microns, a particle size Rocktumbler.com says stays out of most tiny fractures, so it doesn't leave white lines in fractured agate. It rates TXP for agate, jasper, quartz, petrified wood and other stones of about Mohs 5 to 8.
Dosing is straightforward: about 2 level tablespoons per pound of rock plus media in a rotary tumbler, or about 1/2 tablespoon per pound in a vibratory. Run it about a week in a rotary, or 48 to 72 hours in a vibratory. Rocktumbler.com says it uses TXP almost all the time and recommends going straight from 500 or 600 grit to polish.
Pros
- Works on nearly any agate, jasper or quartz
- Less expensive than cerium or tin oxide
- 3 micron size suits stones with fine fractures
- Clear dosing for rotary and vibratory
Cons
- Sold mainly through Rocktumbler.com
- Not the top choice for feldspars
- Overpolishing can bruise stones
Rocktumbler.com TXP Aluminum Oxide Polish
by Rocktumbler.com
Amazon availability: TXP is sold through Rocktumbler.com, and we didn't find it on Amazon.com when we checked in October 2026. If you'd rather order on Amazon, the Rockhound's 1st Choice kit reviewed below includes a 1200 grit aluminum oxide polish, though only enough for one 3 lb batch.
Rocktumbler.com Cerium Oxide Polish 1 lb: Best for Feldspars and Glass
Who it's for: tumblers working with labradorite, moonstone, amazonite, obsidian or glass.
Cerium oxide is the classic quartz and glass polish. Rocktumbler.com says it works on stones of about Mohs 5 to 8, including agate, jasper, quartz, petrified wood, obsidian and feldspar, and also polishes glass. Its polish guide says cerium is preferred for feldspars such as moonstone, labradorite, sunstone and amazonite.
The dose matches TXP: about 2 tablespoons per pound of material in a rotary, and about 1 tablespoon per 2 pounds in a vibratory. Harder stones such as topaz, beryl and tourmaline may need two or more extra days. The catch is cost: Rocktumbler.com says cerium's price rose after a rare-earth shortage, which is why many tumblers switched to aluminum oxide. It's sold in a 1 lb size.
Pros
- Preferred for feldspars
- Excellent on glass and obsidian
- Same simple dose as TXP
Cons
- Much more expensive than aluminum oxide
- Particle size not published
- Not needed for most agate and jasper
Rocktumbler.com Cerium Oxide Polish 1 lb
by Rocktumbler.com
Amazon availability: Rocktumbler.com's cerium oxide wasn't on Amazon.com when we checked in October 2026. If you'd rather order on Amazon, JESCO sells a 1 lb cerium oxide rock polish there, sold by Jesco Products. Start with the same dose of about 2 tablespoons per pound unless JESCO's label says otherwise.
JESCO Cerium Oxide Rock Polish 1 lb
by JESCO
Rocktumbler.com #61 Rapid Polish: Best for Vibratory Tumblers
Who it's for: vibratory tumbler owners chasing the brightest possible shine.
61 Rapid Polish is a much finer aluminum oxide, centered around 0.3 microns. Rocktumbler.com says it gives a brighter shine on some materials, but is designed for vibratory tumblers, not rotary. Dose about 1/2 tablespoon per pound and check after 48 hours.
Use it selectively. Rocktumbler.com says Rapid Polish suits fracture-free materials without cleavage planes, plus obsidian, Apache tears and glass. It warns against using it on feldspars like labradorite and on translucent agate with internal fractures, where the fine particles can enter cracks and leave white lines. It also suggests Rapid Polish on a moistened felt pad for cabochons. Some users add a 1000 grit step before it.
Pros
- Very bright finish on suitable stones
- Small dose in a vibratory
- Also useful on felt for cabochons
Cons
- Not for rotary tumblers
- Can lodge in fractures
- Avoid on feldspars
Rocktumbler.com #61 Rapid Polish
by Rocktumbler.com
Amazon availability: #61 Rapid Polish is sold through Rocktumbler.com, and we didn't find it on Amazon.com in October 2026. We also couldn't confirm an Amazon polish with the same published 0.3 micron size, so we haven't suggested a substitute.
Lortone Rock Tumbler 4-Stage Grit Pack: Best Polish in a Grit Set
Who it's for: Lortone owners and anyone following Lortone's manuals.
Lortone's method uses aluminum oxide for both pre-polish and polish, and its 4-Stage Grit Pack follows it: 16 oz of 60/90 silicon carbide, 14 oz of 150/220, 12 oz of 500+ aluminum oxide pre-polish and 12 oz of fine aluminum oxide polish, rated for up to 12 lb of rock. Lortone's 3A manual calls for 6 level tablespoons of polish in a 3 lb barrel.
Buying polish as part of a matched set means the pre-polish and polish are designed to work together. The pack carries a California Proposition 65 warning for crystalline silica, so pour gently. Our rock tumbler grit guide covers it in full.
Pros
- Matches Lortone's published method
- Aluminum oxide pre-polish and polish
- Enough for several 3 lb batches
Cons
- Mesh size of the polish not stated
- Higher cost per pound than bulk polish
- You pay for coarse and medium grit too
Lortone Rock Tumbler 4-Stage Grit Pack
by Lortone
Amazon availability: Lortone's 4-Stage Grit Pack showed as currently unavailable on Amazon.com when we checked in October 2026, and Lortone sells mainly through lapidary dealers. If you'd rather order on Amazon, the National Geographic Rock Tumbler Grit and Polish Refill Kit is a four-stage alternative sold by Amazon; National Geographic rates it for up to 20 lb of rock and says it works in any tumbler.
National Geographic Rock Tumbler Grit and Polish Refill Kit
by National Geographic
Rockhound's 1st Choice Rock Tumbler Refill Grit Kit: Best Fine Polish for One Batch
Who it's for: first-timers who want one perfect 3 lb batch.
This single-batch kit finishes with 1.5 oz of 1200 white fused aluminum oxide, which the maker rates at 1.5 microns or finer. That's finer than TXP's 3 microns, and comes after a 500 aluminum oxide pre-polish. The kit also includes 60/90 and 120/220 silicon carbide, all pre-portioned for one 3 lb batch.
It's an expensive way to buy polish by the pound, but it's an easy way to try a fine aluminum oxide finish without committing to a bulk bag.
Pros
- Fine 1200 aluminum oxide finish
- Pre-portioned for one 3 lb batch
- Labeled sizes for every stage
Cons
- Highest cost per pound
- Only one batch
- No media
Rockhound's 1st Choice Rock Tumbler Refill Grit Kit
by Rockhound's 1st Choice
Dremel 421 Polishing Compound: Best for Rotary Tools
Who it's for: anyone polishing single stones with a Dremel.
Dremel says its 414 felt polishing wheel, rated for stones, glass and ceramics, works best with the 421 compound. Retail copy describes 421 as a finishing compound for metals and plastics. It's convenient for soft stones and glass on a rotary tool. For quartz-hard stones, cerium oxide or aluminum oxide on felt is the more proven choice. Our guide to Dremel rock polishing covers the method.
Pros
- Made for Dremel felt wheels
- Easy to apply
- Good for glass and soft stones
Cons
- Marketed mainly for metal and plastic
- Not a tumbler polish
Dremel 421 Polishing Compound
by Dremel
Buying Guide: Choosing a Polishing Compound for Rocks
Match the Polish to the Stone
Rocktumbler.com's polish guide:
| Polish | Best for |
|---|---|
| Aluminum oxide (TXP) | Nearly any agate, jasper or quartz |
| Cerium oxide | Agate, jasper, quartz, petrified wood, coral, obsidian, glass; preferred for feldspars (moonstone, labradorite, sunstone, amazonite) |
| Tin oxide | All quartz, jasper and agate; excellent on obsidian; soft stones such as calcite, rhodochrosite and malachite |
| Chrome oxide | Hard materials such as jade, tourmaline and garnet; mixed-mineral rocks such as lapis lazuli, rhodonite and unakite |
Rocktumbler.com notes tin oxide costs several times as much as a good aluminum oxide and is rarely used today.
Particle Size Matters
Finer isn't always better. Rocktumbler.com says TXP's roughly 3 micron particles stay out of most fine fractures, while #61's 0.3 micron particles can enter them and leave white lines in fractured agate. For stones with internal fractures, choose the coarser polish.
Dose by Barrel and Tumbler Type
- Rotary: about 2 level tablespoons per pound of rock plus media, per Rocktumbler.com; Lortone's 3A manual calls for 6 tablespoons in a 3 lb barrel, and its chart gives 12 in a 6 lb barrel and 24 in a 12 lb barrel.
- Vibratory: about 1/2 tablespoon per pound for aluminum oxide, per Rocktumbler.com.
Time by Hardness
The polish stage runs about a week in a rotary for Mohs 7 stones: Lortone and Kingsley North give 5 to 7 days. Rocktumbler.com says harder stones such as topaz and beryl may need about 50% more time, and warns against overpolishing, which can bruise stones or release inclusions. Softer stones polish faster; check them early.
Cushion the Polish Stage
Plastic pellets or broken-in ceramic media protect nearly finished stones from new chips. Kingsley North uses pellets to bring the barrel to 2/3 to 3/4 full in the later stages.
Keep the Polish Clean
Contamination is the biggest polish killer. Clean the barrel, lid, seal and stones thoroughly before adding polish, and keep polish containers closed. If luster is still lacking, Rocktumbler.com suggests burnishing. Our rock tumbler troubleshooting guide covers dull results in detail, and our sea glass guide covers polishing glass.
How We Chose
We didn't test these polishes ourselves. We researched them. We used Rocktumbler.com's polish guides and product pages for particle sizes, doses and stone suitability, Lortone's manuals and pack contents, Rockhound's 1st Choice's listing, and Dremel's accessory pages. We favored polishes whose makers publish clear guidance, and we note that several picks are sold mainly through specialty retailers.
FAQ
What is the best polish for a rock tumbler?
For most rocks, aluminum oxide. Rocktumbler.com says it uses TXP aluminum oxide almost all the time because it's inexpensive and reliable on nearly any agate, jasper or quartz. Cerium oxide is the classic alternative and is preferred for feldspars such as labradorite and moonstone.
Cerium oxide vs aluminum oxide: which is better?
Both work on quartz-family stones. Rocktumbler.com says aluminum oxide polishes such as TXP usually produce fantastic results at a much lower price than cerium oxide, whose cost rose after a rare-earth shortage. Cerium is preferred for feldspars and works well on glass and obsidian.
How much polish do I put in a rock tumbler?
In a rotary tumbler, about 2 level tablespoons per pound of rock plus media, per Rocktumbler.com, or 6 level tablespoons in a 3 lb barrel per Lortone's 3A manual. In a vibratory tumbler, Rocktumbler.com recommends about 1/2 tablespoon per pound.
How long should the polish stage run?
About a week in a rotary tumbler: Lortone and Kingsley North give 5 to 7 days, and Rocktumbler.com runs TXP for about a week. In a vibratory, 48 to 72 hours. Rocktumbler.com says harder stones such as topaz and beryl may need about 50% more time.
Why aren't my stones shiny after polishing?
The polish is rarely the problem. The usual causes are a rushed coarse or pre-polish stage, coarse grit contaminating the polish, or chipped stones. Fix those first, then try a different polish. Rocktumbler.com also suggests burnishing if luster is lacking.
Verdict
For most tumblers, TXP aluminum oxide is the best rock polishing compound: inexpensive, reliable on agate, jasper and quartz, and sized to stay out of fine fractures. Choose cerium oxide for feldspars and glass, and #61 Rapid Polish only in a vibratory tumbler on fracture-free stones.