FINNMARK
Sauna Stones - Grade A Finnish Olivine Diabase 20 kg
Sauna Stones - Grade A Finnish Olivine Diabase 20 kg
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Grade A Finnish olivine diabase is the traditional sauna stone: durable and known for the excellent soft steam it releases when water meets hot rock. The stones suit any sauna heater, wood-burning or electric, and come in two sizes, 5–10 cm and 10–15 cm, so you can match the grade your heater specifies. Where a heater calls for both, the larger stones sit at the base with the smaller grade layered on top. Each box contains approximately 20 kg, and as a natural material some colour variation between stones is entirely normal.
- Grade A quality: Premium Finnish olivine diabase, noted for its durability.
- Soft steam: Releases an excellent, soft steam when water is ladled over the stones.
- Fits any heater: Suitable for wood-burning and electric sauna heaters alike.
- Two sizes: Choose 5–10 cm or 10–15 cm to match your heater's requirement.
- Correct layering: Where both grades are needed, larger stones go at the base and smaller on top.
- Simple to check: Replace stones once they have worn smaller than your closed fist.
- Natural material: Some colour variation between stones is normal.
| Stone type | Grade A Finnish olivine diabase |
| Stone sizes | 5–10 cm or 10–15 cm |
| Box weight | Approximately 20 kg |
| Suitable for | All wood-burning and electric sauna heaters |
| Appearance | Natural stone; some colour variation between stones is normal |
| Stone requirements by heater (kg) | |
| Wood-burning heaters | |
| Luosto & Luosto Water Tank | 35 kg |
| Inari | 40 kg (5–10 cm) + 20 kg (10–15 cm) |
| Kuru 14 & 14 Water Tank | 35 kg |
| Kuru 20 | 40 kg |
| Narvi NC 16 | 50 kg |
| Narvi NC 20 & 20 Water Tank | 60 kg |
| Narvi NC 24 | 80 kg |
| Narvi Stony | 60 kg (5–10 cm) + 150 kg (10–15 cm) |
| Narvi Steam Master | 100 kg |
| Narvi 30 | 60 kg |
| Narvi 50 | 100 kg |
| Narvi Velvet | 100 kg (5–10 cm) + 60 kg (10–15 cm) |
| Aito 16 & 16 Water Tank | 50 kg |
| Aito 20 & 20 Water Tank | 60 kg |
| Aito 24 & 24 Water Tank | 80 kg |
| Electric heaters | |
| Narvi Velvet Electric | 140 kg |
| Narvi Slim | 30 kg |
| Narvi NM | 30 kg |
| Narvi Softy | 120 kg |
| Narvi Style | 60 kg |
| Narvi Steam Ready | 80 kg |
| Narvi NC Electric | 30 kg |
| Narvi Saana | 80 kg |
| Commercial sauna heaters | |
| Narvi Ultra | 50 kg |
| Narvi Ultra Big | 120 kg |
| Narvi Ultra Small | 30 kg |
| Narvi Style Pro | 80 kg |
Loading the stones
For wood-burning and electric heaters, fill the stones to the rim without exceeding it, leaving the gaps as open as possible for water and air to flow through. Where both grades are required, place the larger stones at the base and the smaller grade on top. This creates a soft, even löyly. Guides and video demonstrations are available at finnmarksauna.com.
Care and replacement
Even high-quality diabase eventually fractures. Depending on use, replace the stones every one to two years to keep the gaps open and maintain heat capacity. Replace them sooner once they have worn smaller than your closed fist.
Brand
Quarried Finnish olivine diabase, supplied by Narvi.
Ordering
Sauna stones ship as heavy boxed goods. If you are unsure which grade or quantity your heater needs, contact support@finnmarksauna.com before ordering.
We offer fast and reliable delivery to customers across the UK and beyond. For full details on shipping times and costs, please review our delivery policy.
We offer hassle-free returns within 30 days of purchase, so you can shop with complete confidence. For details, see our returns policy.
We are committed to delivering products of the highest quality, for details surrounding warranty please contact us.