Choosing the right sauna stones is just as important as selecting your sauna heater. Whether you're using a traditional electric, wood-burning, or modern design heater like HUUM or Harvia, the stone shape and material directly affect steam quality, heater longevity, and heat-up times.
In this article, we’ll break down the differences between rounded sauna stones and split-face (jagged) stones—and help you determine which is best for your sauna setup.
Split-Face Sauna Stones (Jagged)
Split-face stones are sharp-edged, rough-cut stones (usually olivine diabase) that stack tightly and create high surface contact. This makes them ideal for producing strong, fast steam (“löyly”).
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Best for: Electric heaters with heating elements running through the stones (Harvia KIP, Cilindro, Club, Virta)
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Heat Transfer: Excellent—high surface area speeds up heat-up time
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Steam Production: Sharp edges create intense bursts of steam when water is poured
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Maintenance: May require replacement more frequently due to cracking or fragmentation
→ Shop Harvia Split-Face Sauna Stones (5–10cm)
Rounded Sauna Stones
Rounded sauna stones are tumbled smooth for gentler heat release and softer steam. They are typically made from high-density olivine and are ideal for exposed-style sauna heaters like HUUM.
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Best for: Exposed heater designs (HUUM DROP, HIVE, CLIFF, STEEL, Saunum, Harvia Spirit)
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Steam Quality: Softer, longer-lasting steam
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Air Circulation: Better airflow between stones helps prevent overheating
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Longevity: Last longer than split-face and are less prone to cracking
→ Shop Harvia Rounded Olivine Sauna Stones (2–4")
→ Shop HUUM Rounded Sauna Heater Stones
Performance Comparison: Rounded vs Split-Face
| Feature |
Split-Face Stones |
Rounded Stones |
| Steam Intensity |
High, aggressive steam |
Gentle, longer-lasting steam |
| Heat-Up Time |
Faster due to greater surface contact |
Moderate, but more consistent |
| Air Circulation |
Tighter stack may reduce flow |
Better airflow between stones |
| Durability |
More prone to cracking |
Longer-lasting and heat-resistant |
| Ideal Heater Type |
Harvia, (heating elements inside stone cage) |
HUUM, Saunum, Harvia Spirit (exposed-style heaters) |
Which Sauna Stone Should You Choose?
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Choose Split-Face Stones if you want fast heat-up times and strong steam output, especially in traditional electric or wood-fired heaters like Harvia or Saunum.
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Choose Rounded Stones if you're using a design heater like HUUM and prefer smooth, luxurious steam with better air circulation.
Pro Tip: Always follow your heater manufacturer’s stone recommendations to ensure proper performance and avoid damaging the elements.
→ Browse All Sauna Stones
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