About 2,800 million years ago, magnesium-rich komatite lava erupted from fissures in the Earth’s crust in the area that is currently Eastern Finland. The 1,600-degree-hot lava swiftly spread far from the sites of the eruptions as undersea flows.
Between 1,900 and 1,800 million years ago, the tectonic plates of the Earth’s lithosphere collided in the area that is now Finland. This collision created the Svecofennian mountain chain, which was comparable to the Alps, and plucked ancient lava flows and their olivine into an almost vertical position inside the base of the mountain chain.
The pressure at a depth of close to ten kilometres beneath the ancient mountain chain was 2,000–4,000 atmospheres and the temperature 400-500°C. Aqueous solutions containing carbon dioxide flowed through the bedrock pores, transforming the olivine first into serpentine stone and finally into soapstone. This many-phased metamorphosis progressed in fronts and lasted tens of millions of years.
Nature’s dramatic show ended in a rare natural phenomenon: soapstone had been born.