Peridotite Sauna Stones: Dense and Durable
Peridotite is a very dense igneous sauna stone that stores heat well and resists cracking. Here is how peridotite compares to olivine diabase and when to choose it.
The short answer
Peridotite is a very dense, heavy igneous rock that makes an excellent, long-lasting sauna stone. Like olivine diabase, it stores a lot of heat and resists thermal shock, giving a strong, even löyly.
Peridotite sits alongside olivine diabase at the top of the sauna-stone list. It is one of the densest rocks used in saunas, which is exactly what you want in a stone.
Why peridotite works
- Very dense and heavy. It packs a lot of thermal mass into each stone, storing plenty of heat for löyly.
- Low porosity. It traps little water, so it resists the cracking that ruins porous rock.
- Thermal-shock resistant. It tolerates repeated rapid heating and cold dousing.
- Long-lasting. Its durability rivals the best sauna stones.
Peridotite vs. olivine diabase
| Peridotite | Olivine diabase | |
|---|---|---|
| Density | Very high | High |
| Heat storage | Excellent | Excellent |
| Availability | Good | Very common |
| Verdict | Premium, durable | The standard |
Both are excellent; olivine diabase is simply more common and slightly cheaper. If you can get peridotite, it is a superb choice — see the full field in best sauna stones.
Getting the best from it
Peridotite is a connoisseur choice that performs at the very top of the range. Buy it sold for saunas, load it well, and refresh it when it eventually crumbles, and it will deliver a deep, soft steam for years.
Handling a heavy, dense stone
Peridotite delivers its excellent heat storage because it is so dense — but that density means it is heavy, so keep an eye on your heater rated stone capacity by weight rather than simply filling the space. Load it the same way as any sauna stone: rinse it, place the largest pieces at the base for mass and airflow, and grade up to smaller stones on top, keeping the whole pile loose so it breathes.
The payoff for the extra weight is a deep, generous, long-lasting löyly and stones that hold up well to years of heat cycling. Peridotite is less common and a touch pricier than the standard olivine diabase, so it is often a connoisseur choice rather than a default — but if you can source it, loaded correctly it performs at the very top of the range. Refresh the pile when it eventually crumbles, and it will reward you with soft, strong steam for a long time.
For anyone building a sauna they intend to keep and use often, peridotite is a stone worth seeking out. Its density gives a deep, generous löyly and years of service before it needs refreshing, and while it is a little heavier and pricier than the standard, the payoff is a stone that performs at the very top of the range. Where availability allows, it is a connoisseur choice that quietly elevates the steam.
Frequently asked questions
What is peridotite?
A very dense, heavy igneous rock used as a premium sauna stone. Its density and low porosity give excellent heat storage and strong resistance to thermal-shock cracking.
Is peridotite better than olivine diabase for saunas?
Both are excellent. Peridotite is very dense and durable; olivine diabase is the more common, slightly cheaper standard. Either makes a strong, even löyly when loaded well.
Does peridotite last a long time in a sauna?
Yes — its density and durability rival the best sauna stones, so it holds up well to years of heat cycling before needing a refresh.
Is peridotite heavy?
Yes, it is one of the denser rocks used in saunas. Mind your heater rated stone capacity by weight when loading it, and still stack loosely for airflow.
Where can I buy peridotite sauna stones?
From sauna suppliers that stock it, sold specifically as sauna stones. It is less common than olivine diabase but widely regarded as a premium option.
Is peridotite too heavy for a sauna heater?
Not if you respect the heater rated stone capacity by weight rather than just filling the space. Peridotite is dense and heavy, which is what gives its excellent heat storage — load to the rated weight and stack loosely.
How do you load peridotite sauna stones?
The same as any sauna stone: rinse them, place the largest at the base for mass and airflow, grade up to smaller stones on top where water lands, and keep the pile loose so it breathes.
Is peridotite worth choosing over olivine diabase?
Both are excellent. Peridotite is very dense and durable but less common and a touch pricier, so it is often a connoisseur choice. Olivine diabase is the more available, economical standard. Either makes a strong löyly.
Is peridotite a good long-term sauna stone?
Yes — its density gives a deep, generous löyly and years of service before refreshing. It is a little heavier and pricier than the standard olivine diabase, but performs at the very top of the range where you can source it.
