Understanding Sauna Stones and Their Heat-Retaining Properties

Sauna stones exhibit core properties crucial for generating steam and the optimal sauna experience. Their main function is the efficient heat retention uniformly discharged during a sauna bathing session. Read on to understand sauna stones and their heat-retaining properties.

What are the Properties of Sauna Stones?

The visual aspect of home sauna stones depends on personal preference. Generally, stones used in saunas must sustain frequent heating and cooling phases.  They must be highly durable and capable of facilitating heat generation across the sauna. In addition, resistance to thermal shock is crucial for sauna stones in contact with hot stoves.

Some stones, such as volcanic rocks, are porous, which means they absorb water to generate steam. The ideal sauna stones must be non-reactive to water to prevent the discharge of toxic substances during heating. Aesthetics are vital for the overall ambiance of the sauna. Visually appealing textures and colors improve the sauna experience. Sauna stones that possess these properties are ideal for an enjoyable and effective sauna experience. 

Where Sauna Stones are Sourced

Sauna stones are sourced from different countries globally. Their availability depends on the geological features of every region. For instance, cultural traditions in Finland conform to the use of stones such as peridotite, gabbro, and basalt. In Russia, where the geological landscape is diverse, commonly used stones include shungite, diabase, and gabbro.

Nordic countries like Norway and Sweden often use locally sourced gabbro and granite. In Iceland, volcanic rocks like basalt are readily available due to the volcanic activity in the country. Durable granite is used in Brazil, while soapstone is preferred in India. Igneous rocks, such as diabase, facilitate sauna heating in South Africa. 

Types of Sauna Stones

Here are the types of stones you may consider for your sauna.

·       Basalt

Basalt stones originate from volcanic rock and have dominant heat distribution and retention properties. These dark gray or black stones can be found in regions with volcanic activity and effectively absorb and retain heat.

When heated by wood-burning stoves or electric sauna heaters, basalt stones discharge stored heat, providing a comfortable and consistent sauna temperature. They are renowned for their exceptional durability and ability to resist high temperatures without splitting. Their somewhat porous but smooth texture provides a comfortable surface, facilitating steam distribution once water is poured over them. Basalt stones have cultural and therapeutic importance and are often linked to hot stone massages.

·       Granite

Granite is a coveted sauna stone renowned for its powerful heat-retaining properties, aesthetic versatility, and durability. Granite is composed of minerals such as mica, feldspar, and quartz. It can resist repeated heating and cooling in saunas without cracking, ensuring users' comfort during sauna sessions. Further, it is available in different colors, including shades of pink, gray, brown, black, and red, making it a go-to option for outdoor saunas globally. Granite’s visual appeal improves the overall ambiance in the sauna.

·       Diabase

Also known as dolerite, diabase stones are igneous rocks created when molten lava cools. They range in color from dark gray to black and have a medium to coarse texture. Diabase stones are mainly composed of pyroxene, plagioclase feldspar, and olivine. Besides their durability, diabase stones are resistant to weathering, which is why they are used in saunas and for construction. Since they are fine-grained, these stones have exceptional strength and can withstand high temperatures. They also possess powerful heat retention and stream generation properties. 

·       Peridotite 

Peridotite is composed of pyroxene and olivine. It has unique heat retention and distribution properties. When heated, the stone maintains warm for a prolonged period, making it a consistent and stable heat source in the sauna. The mineral composition of peridotite facilitates the even distribution of heat, ensuring the environment remains comfortable with heat spreading throughout the stones for uniform warmth inside the room. The stone is believed to discharge natural minerals, which some believe can help promote well-being.

Moreover, peridotite’s ability to emit infrared radiation and retain heat has been found to enhance detoxification, relaxation, and circulation during sauna sessions. Peridotite’s green hue adds a visually appealing natural element to saunas, giving them a rejuvenating, earthy atmosphere that boosts the overall experience. It’s tough and dense, meaning it can withstand frequent heating and cooling without breaking or cracking, making it a durable option for saunas. 

·       Gabbro

Gabbro is a dark-colored, coarse-grained igneous rock that forms after the slow cooling and solidification of magma below the earth’s surface. It’s composed of minerals like pyroxenes, plagioclase feldspar, and olivine. Gabbro is a high thermal mass that absorbs and stores high amounts of heat. When heated, the stone slowly discharged the heat over time, providing a consistent and steady temperature in the sauna.

Gabbro relies on its coarse and dense properties to distribute heat evenly across the unit. This prevents sudden temperature surges or hot spots, creating a relaxing and comfortable environment. Gabbro is renowned for its durability. It can withstand high temperatures without degrading or cracking.

The stone is chemically stable, meaning it doesn’t discharge toxic substances when heated, making it a safe option for use in the sauna. Gabbro’s smooth texture and dark color make it visually appealing. Moreover, it has a natural earthy appearance that blends well, creating a calming environment. The stone’s durability makes it capable of performing over time, regardless of the frequency of use. 

·       Soap Stone

Soapstone is a metamorphic rock mainly comprising talc with some micas and pyroxenes. It’s smooth and soft to the touch, and its color ranges from gray to blue, brown, and green. Soapstone has excellent heat retention capabilities, and its mineral composition facilitates even heat distribution. It resists cracking under extreme temperatures, making it a good sauna stone option. The steam and heat from soapstone are soothing and gentle.

Since soapstone is non-reactive, it’s safe to use in high-heat environments. Moreover, the stone doesn’t discharge harmful fumes or substances when heated, making it ideal for use in the sauna. Cleaning and maintaining soapstone is easy, keeping the sauna fresh. 

·       Serpentine

Serpentine is a metamorphic stone characterized by gray, green, and brown color. It has a fibrous and smooth texture and is formed through the modification of magnesium-rich rocks like dunite and peridotite in the earth’s crust. Serpentine has unique thermal properties, enabling it to retain heat effectively. The stone absorbs heat and discharges it slowly, making it a suitable sauna stone because it maintains a soothing and consistent temperature. Serpentine is resistant to breaking or cracking under frequent heating and cooling.

Further, the stone does not produce toxic gases or substances when heated. It is also non-flammable, making it safe during intense sauna conditions. Serpentine’s surface can be polished to a smooth finish. In some cultures, the stone has been linked to energy-balancing and healing effects, with some sauna enthusiasts believing serpentine can promote relaxation and well-being, boosting the therapeutic effects of saunas. 

Finally

Sauna stones combine cultural, traditional, and scientific significance to make them functional heat retainers. Their ability to absorb, retain, and discharge heat creates a convenient and therapeutic environment, making saunas some of the most adored units worldwide. Each sauna stone is crucial in delivering the rejuvenating, relaxing, and shared warmth associated with saunas. Understanding the properties of different sauna stones helps you make an informed choice to ensure a consistent and enjoyable experience.