Products · Building a sauna · Harvia
Harvia AC3000 Sauna Heater Stones, olivine diabase, 5 to 10 cm, 20 kg box
Reader ratings
Angular dark-gray olivine diabase stones, matching the olivine-dolerite Harvia’s manual lists as suitable. Nothing is added, but Harvia publishes no analysis and says stones crumble and need rearranging yearly.
Best for Owners of an electric sauna heater who need heater stones of the kind its manual calls for, at a low price per kilogram.
- Our rating
- Good (3.7 of 5)
- Price range
- Budget
- Size
- Angular split-face stones, 5 to 10 cm, 20 kg (44.1 lb) per box; a Cilindro PC90 takes about five boxes
- Made in
- Finland (olivine diabase mined in Western Finland, per Harvia)
approx. $69.50 for one 20 kg (44 lb) box, Finnish Sauna Builders, 2026-10-23
See it on Harvia’s site → (opens in a new tab)We are not affiliated with Harvia. This link goes to the maker’s own page, with no tracking code. How we're funded.
Also sold at Finnish Sauna Builders ($69.50 per 20 kg box), Haven of Heat ($59.00 per 44 lb box), Amazon ($135.00 per 44 lb box) .
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How we evaluated it
How it scores Our rating, metric by metric
- Materials 45% of the rating 4 of 5
One named rock, olivine diabase (also called dolerite), which matches the olivine-dolerite in Harvia’s heater manual, with nothing added, but the “no harmful ingredients” claim has no analysis behind it.
- Durability 20% of the rating 3 of 5
Harvia’s manual says sauna stones disintegrate in use and should be rearranged at least once a year, with cracked ones replaced; angular diabase holds heat well.
- Safety 10% of the rating 3 of 5
Harvia gives size guidance (5 to 10 cm for its Cilindro heaters, 10 to 15 cm for large electric heaters and all wood-burning stoves) and warns that under-filled stone space is a fire risk, but publishes no radioactivity or dust test.
- Trust 10% of the rating 4 of 5
A named maker with a US office, a plain data sheet and a user manual, and no CPSC recall or Prop 65 notice found; its stone claims are its own.
- Value 15% of the rating 4 of 5
About $3.48 per kilogram at Finnish Sauna Builders ($2.95 at Haven of Heat plus $50 per-box shipping unless bought with a heater), close to the cheapest sauna stone we found and below HUUM’s boxes at about $5.33 per kilogram.
The rating, 3.7 of 5, is the weighted average of these scores. See how we rank building a sauna and our standard.
Where to buy Stores and the prices we saw
- Finnish Sauna Builders (opens in a new tab) approx. $69.50 per 20 kg box. Illinois sauna retailer that lists Harvia as a brand. Harvia shows no price on its own site; the price above is the store’s.
- Haven of Heat (opens in a new tab) approx. $59.00 per 44 lb box. Sold as the AC3000, olivine diabase mined in Western Finland. The page adds $50 per box for shipping unless the stones ship with a sauna stove or heater.
- Amazon (opens in a new tab) approx. $135.00 per 44 lb box. Sold and shipped by Harvia US, the brand. Listed as olivine diabase, 5 to 10 cm, 44 lb box, but under item number SN-AC-ROCK rather than AC3000, so confirm it is the same stone.
Prices as we saw them on October 23, 2026. They change often. These links carry no tracking code and earn us nothing.
What it’s made of What touches your food, water, skin or air
- Dark gray olivine diabase (also called dolerite), split-face angular stones, 5 to 10 cm, 20 kg per box; Harvia says it is a subvolcanic rock mined in Western Finland
- Harvia says the stones do not contain harmful ingredients (no analysis published)
What people ask Worries raised online and elsewhere, and what we found
- Which stones are safe to use in a heater?
- Harvia’s heater manual (opens in a new tab) says to use angular split-face stones of peridotite, olivine-dolerite or olivine, and not light, porous ceramic “stones” or soft soapstone, which do not absorb enough heat. It adds that a heater run without stones, or with its stone space under-filled, is a fire risk.
- Do the stones crack, and how long do they last?
- The same manual says stones disintegrate in use because of the swings in temperature, and that you should rearrange them at least once a year, remove broken pieces and replace crumbled stones. Harvia sells a heat-treated version, the AC3050 (opens in a new tab), “for busy saunas” and says the treatment gives a longer service life.
- Do they contain anything harmful?
- Harvia’s page says “does not contain harmful ingredients” and the stones are dark gray olivine diabase. No analysis (heavy metals, radioactivity, quartz dust) is published. Washing the stones before piling, as the manual advises, removes loose dust.
- Which size do I need?
- Harvia’s page says to check the right size for your heater in its manual. The Cilindro manual calls for 5 to 10 cm stones (AC3000), while Harvia’s AC3020 page (opens in a new tab) gives 10 to 15 cm for large electric heaters and all wood-burning heaters.
Why we chose it What put it on our list
- One named rock, olivine diabase (also called dolerite), dark gray and angular, which matches the olivine-dolerite the heater manual names as suitable.
- Split-face angular stones store heat and pile with good air circulation, according to Harvia.
- At $2.95 to $3.48 per kilogram at two stores it is among the cheapest sauna stones we found.
Trade-offs What to weigh before you buy
- No analysis is published for heavy metals, radioactivity or dust, only a “no harmful ingredients” statement.
- Stones crumble with use and must be rearranged yearly and replaced as needed.
- Wood-burning stoves and some electric heaters need other sizes, so check the manual before buying.
- Prices are a store’s, and they differ a lot (Harvia US’s Amazon listing for this size is $135 a box); a heater takes several boxes (a Cilindro PC90 takes about five), and a store may charge $50 shipping per box.
What to know Details worth knowing first
Steam in a traditional sauna comes from water thrown on hot stones, and the stones matter. Harvia’s heater manual says to use angular split-face stones of peridotite, olivine-dolerite or olivine, and not light porous ceramic “stones” or soft soapstone. The AC3000 is dark gray olivine diabase in 5 to 10 cm pieces, 20 kg a box, mined in Western Finland according to Harvia.
There is nothing in the box but rock, and that is all we can say for sure. Harvia says the stones contain no harmful ingredients and publishes no analysis. The manual also says stones crumble with use: rearrange them at least once a year, take out the pieces and replace stones that have broken down.
A heater takes several boxes (a Cilindro PC90 takes about five), so the price per kilogram matters. It is $2.95 to $3.48 at two stores, among the cheapest we found, and $6.75 on Harvia US’s own Amazon listing. Check your heater’s manual for the right size.
What we checked Each claim, and how sure we are of it
| What we checked | What we found |
|---|---|
| Dense rock made for sauna heat Maker’s claim | Dark gray olivine diabase (also called dolerite), which matches the olivine-dolerite that Harvia’s heater manual lists among suitable stones, with peridotite and olivine. Harvia says the stones store heat well. |
| Nothing added Maker’s claim | Natural split-face stones with nothing added, per Harvia’s description. |
| Harmful ingredients Not verified | Harvia says “does not contain harmful ingredients”. No analysis is published, so this is not verified. |
| Size guidance Maker’s claim | 5 to 10 cm for the Cilindro, per its manual; the manual tells you to check your heater’s size and describes how to pile the stones and when to replace them. |
| Recalls and notices Verified | No recall naming Harvia in the US Consumer Product Safety Commission data and no Prop 65 notice in the California Attorney General’s search, both on 2026-10-23. |
What the labels mean
- Verified We opened an independent record that confirms it: a certifier’s listing, a regulator’s list or a lab report. It is linked under Sources.
- Maker’s claim The maker says so on its own page or label. We read it but found no independent record.
- Not verified We looked and could not confirm it, or the maker does not say. Treat it as unknown.
Sources Where our facts come from
- Harvia AC3000 sauna heater stones: maker’s US product page. Maker’s page. Stone species, size, box weight, Western Finland and the “no harmful ingredients” line, seen 2026-10-23. Open ↗ (opens in a new tab)
- Harvia Cilindro installation and user manual (PDF). Maker’s page. Suitable stone types, what not to use, piling, yearly rearranging and the fire warning. Open ↗ (opens in a new tab)
- Harvia AC3020 sauna heater stones, 10 to 15 cm. Maker’s page. The larger size, for large electric heaters and all wood-burning heaters. Open ↗ (opens in a new tab)
- Harvia AC3050 sauna heater stones (heat-treated). Maker’s page. The heavy-duty alternative. Open ↗ (opens in a new tab)
- Finnish Sauna Builders: Harvia sauna stones AC3000. Independent source. Store price per box and size advice, seen 2026-10-23. Open ↗ (opens in a new tab)
- Haven of Heat: Harvia split-face olivine diabase sauna heater stones, AC3000. Independent source. Store price per box and the $50 per-box shipping note, seen 2026-10-23. Open ↗ (opens in a new tab)
- Amazon: Harvia sauna rocks for electric heater, standard size, olivine diabase 5-10 cm, 44 lb box. Independent source. Sold and shipped by Harvia US; item number SN-AC-ROCK. Seen 2026-10-23. Open ↗ (opens in a new tab)
- Finnish Sauna Builders: HUUM sauna heater stones, 33 lb box. Independent source. Used to compare the price per kilogram ($80 for a 33 lb box). Open ↗ (opens in a new tab)
- US Consumer Product Safety Commission: recall search. Certifier or regulator listing. Returns no recall for Harvia (2026-10-23). Open ↗ (opens in a new tab)
- California Attorney General: Proposition 65 60-day notice search for Harvia. Certifier or regulator listing. No matching records (2026-10-23). Open ↗ (opens in a new tab)
Alternatives Other options to compare
- Harvia AC3050 heat-treated olivine diabase (opens in a new tab) A heavy-duty version for busy saunas; Harvia says micropores soften the steam. Higher price.
- Finlandia Sauna Finnish peridotite stones (opens in a new tab) A 45 lb box at about $69.50 from Finnish Sauna Builders, about $3.41 per kilogram. Peridotite is also on Harvia’s manual list.