Uncategorized, Sauna Design, Sauna Guide

Why Sauna Rocks Are Important and Where To Find Them


Sauna rocks are the keepers of the heat, the conductors of comfort, the heart and soul of the whole sauna experience. No rocks, no sauna.

Ideally they are hand-picked, carefully prepared, and heated to the perfect temperature; they transform a simple wooden room into a haven of tranquility and rejuvenation. And let’s be honest, what could be more fundamental to the sauna experience than that sizzling sound as water meets the hot rocks, followed by the enveloping wave of löyly, the soul-cleansing Finnish steam?

But have you ever paused in your pre-sauna anticipation to ponder where these rocks come from? What makes a stone suitable for a sauna? How did the Finnish people select and source these unique rocks with their deep-rooted sauna traditions?

Today, we’re stepping out of the sauna for a bit – don’t worry, we’ll be back soon- to stroll into the wilderness and unearth the story of Finnish sauna rocks. We’re bringing you secret insights from the North Shore of America to Eastern Finland, from the traditional rituals of sourcing sauna stones to their special characteristics.

So grab a towel, hydrate, and dive deep into the heart of sauna culture. It’s time to turn up the heat and start our exploration into the Finnish art of finding the perfect sauna rocks. Sit back, relax, and let’s get streaming!

The History of Sauna Rocks

Ancient Sauna Traditions

Early indications of heat-based bathing date back to 3500 BC, with Marden Henge in England providing evidence of the ancient relationship between humans, heat, and stones. The findings from the University of Reading’s excavation team uncovered charred fragments of stones and an indoor fire pit, illustrating how our ancestors practiced sauna-like activities. Interestingly, the core principles of these primitive saunas closely resemble the design elements in today’s models.

Native American Sweat Lodges: An Ancient Sauna Variant

Native American tribes have held sacred the practice of heat-based bathing for centuries, using stones in a ceremonial context. This tradition of using hot stones within sweat lodges, as illustrated in Mikkel Aaland’s book “Sweat,” reveals an intimate connection between human spirituality, wellness, and nature.

In these rituals, fire-heated stones were brought into a sweat lodge, often placed in the northern corner to ward off the malevolent north wind — considered the carrier of colds and sinister illnesses. After the stones glowed red, the participants entered the darkened space; their senses heightened due to the sudden loss of vision. The radiant heat from the glowing stones, the texture of the ground beneath them, and the companionship of their peers heightened their awareness.

A mixture of water, cedar, and piñon needles would be poured onto the hot rocks, resulting in a surge of nearly unbearable hot vapor that left as quickly as it arrived. This left a lingering pleasant odor of burned needles, which, according to tradition, had curative properties. The participants were encouraged to inhale and drink the resinous brew, believed to promote wellness.

Evolution of Sauna Heating Techniques

From native sweat lodges to smoke saunas and the eventual development of chimneys and electric stoves, our ancestors continually innovated to enhance their sauna experiences. Today, we relish the comfort of continuously heated saunas, a luxury that owes itself to integrating chimneys and electrical heating systems.

The Science and Importance of Sauna Rocks

The Unique Heat Distribution of Sauna Stones

Just as in ancient sweat lodges, modern sauna rocks offer unrivaled heat distribution, superior to other heating sources like open fire or metal elements. The physical properties of these stones enable them to absorb, retain, and gradually release heat, creating a flowing, gentle steam typical of a great sauna. The steam produced when water is poured onto these heated stones intensifies the heat, creating an immersive sauna experience reminiscent of ancient traditions.

The Impact of Sauna Stones on Air Quality

Research suggests that the steam, or loyly, generated from heated stones can increase the presence of negative ions in the air, contributing to a refreshing sauna experience. These negative ions are associated with feelings of refreshment and vitality, similar to the sensations one might experience after a rainstorm or near a waterfall. In essence, sauna stones heat your sauna and enhance the air you breathe, harking back to the purifying rituals of ancient sweat lodges.

Sauna Rocks Today

Changing Trends in Sauna Design

The sauna industry has seen a noticeable shift from the industrial, stone-light designs of the 20th century towards minimalist stoves that prominently display an abundance of stones. Stones are no longer hidden or minimized; they are celebrated for their aesthetic appeal and fundamental role in creating heat and steam.

The Rise of “Instagrammable” Sauna Experiences

The most popular sauna heaters and stoves today are rock basket sauna heaters that put the rocks front and center of the design. This is not only for a modern look, but to reduce the amount of ‘harsh’ radiant heat, letting the rocks and loyly do more of the work through conduction and convection.

Sauna heaters, like this HUUM HIVE in a Haljas Glass Sauna put the sauna rocks as the star of the show.

Today’s saunas are not just about heat and relaxation; they also prioritize aesthetics and design. Sauna builders treat stoves as works of art, emphasizing the beauty of the rocks within them. This results in unique and captivating sauna designs and aligns with modern trends to create photogenic, serene, and restorative environments.

Choosing the Right Sauna Stones

Which Rocks Are Suitable for Sauna?

When selecting the right stones for your sauna, understanding their heat absorption and release capacities is critical. Not all rocks are created equal; volcanic rocks such as basalt and olivine are often favored for their superior heat retention and durability. Conversely, rocks like shale or sandstone should be avoided as they can shatter under intense heat.

In Finland, the most commonly used stones for saunas are olivine-dolerite and peridotite, specifically a variety known as “vihreäkivi” or “greenstone.” These are primarily found in the eastern part of the country, particularly in the region of Kainuu.

These rocks are part of the Karelian domain, a geological area rich in greenstone belts. The greenstone found here has excellent heat retention and release capacities, which make it highly sought after for sauna use.

Harvesting Sauna Stones Responsibly

While Finnish landscapes are abundant in olivine and peridotite, it’s crucial to remember that collecting stones should be done responsibly and sustainably. Always remember the principle of “jokamiehenoikeus,” or “every man’s right,” a traditional Finnish concept advocating for respectful and harmonious interaction with nature.

This includes not causing harm to nature or disturbing others while collecting stones. Many locations, including Lake Superior, where many Minnesotans and Wisconsinites collect rocks are protected and require permission for any stone collection, so always verify the specific area’s rules and regulations before proceeding.

Preparing Natural Stones for Sauna Use

Once collected, the stones need to be prepared for sauna use. They should be thoroughly washed to remove any dirt or loose fragments. Depending on their size, they may need to be broken into smaller pieces, ideally around 10-15 cm in diameter. Lastly, the stones should be dried properly before placing them into the sauna stove.

The Finnish tradition is rich in understanding the natural resources required for a quality sauna experience. By following these guidelines, anyone can bring a touch of the Finnish sauna tradition into their home. Yet, as we immerse ourselves in this historical culture, we must remember our responsibility to nature and ensure our actions are sustainable and respectful to the environment.

Sauna Stone Safety and Maintenance

Ensuring safety in the sauna means paying close attention to the type, shape, and arrangement of stones. Also, knowing when to replace them is essential. Keep a keen eye on the stones for signs of cracking or crumbling. Regular cleaning is also critical to remove accumulated dirt or grime and ensure efficient heat transfer.

Modern rock basket sauna heaters provide impressive (minimal) clearances allowing the sauna to get much closer to combustible surfaces without extra heat shields. Always check the sauna manual to confirm clearances before purchasing and again before installation.

The Timeless Appeal and Importance of Sauna Rocks

From ancient times to the present day, sauna rocks have remained at the core of the sauna experience, shaping our health, our sauna traditions, and even our architectural design preferences. They embody a simple yet profound principle: nature, in its raw and unprocessed form, has an immense capacity to heal, restore, and inspire. Indeed, every hot steam and sweat drop in a sauna is a testament to these remarkable stones’ enduring power and appeal.


Won’t it void my heater warranty if I collect my own rocks?

Many sauna websites, including Sauna Marketplace (in some cases) claim that you must purchase sauna stones from the manufacturer for the warranty to be valid. In general, this is not an issue for wood-burning saunas. The main issue is that when rocks are not sized properly in electric saunas their heating elements can soften when hot and touch. This causes the heating elements to self-destruct. In most cases, the warranty specifies certain size for rocks but does not require the customer to purchase from them.

What type of rocks are best for sauna use, and where can I find them?

Volcanic rocks like basalt and olivine are often used in saunas due to their excellent heat retention and durability. In Finland, the most common sauna stones are olivine-dolerite and peridotite, specifically a variety known as “vihreäkivi” or “greenstone,” primarily found in the eastern part of the country, particularly in the region of Kainuu.

Anything to consider when collecting sauna rocks?

Sauna stones should be collected responsibly and sustainably, respecting nature and adhering to the rules and regulations of the specific area. After collection, they should be thoroughly washed to remove any dirt or lose fragments, potentially broken into smaller pieces if necessary, and properly dried before placing them into the sauna stove.