What is Shirasu
An unparalleled volcanic product
Shirasu is volcanic ejecta that was created 25,000 years ago by a massive volcanic eruption in southern Japanese archipelago. The magma expelled by the eruption formed a massive pyroclastic flow that was deposited so quickly that the shirasu it contained formed a thick layer in the strata before it could mix with other types of soil.
Unique magma ceramic material
Shirasu is a natural inorganic ceramic material created by magma, which we refer to as “magma ceramic”. Shirasu is also known as “amorphous volcanic glass”, and possesses an amorphous portion ranging from 60% to 80%, giving it unique properties which distinguish it from other volcanic products.
Being highly amorphous, its molecular composition is unstable and activated, and according to the environment, it easily causes a catalytic reaction.. Therefore, it inherently exhibits functions such as deodorization, decomposition, sterilization, and ionization.
Porous structure and composition of diverse substances
Shirasu has a porous structure featuring numerous holes in extremely ﬁne particles.
Conposition of shirasu
Shirasu and Magma
Soil is rock that has been weathered into powder. It develops over a long period of time, affected by various environmental factors such as biological and meteorological influences. Soil supplies nutrients and water to plants and is an essential provider for the foundations of all organic life, starting with us – humans.
Shirasu, in turn, is the result of a pyroclastic flow of magma which instantaneously cooled as it erupted, and has the same physical characteristics as finely ground inorganic rock. It therefore can be considered a primitive soil that is untouched by the actions of plants or microorganisms.
‘Magma Soup’ Fostered Life on Earth
Magma erupting into ancient oceans was slowly cooled into minerals that gradually dissolved and released various elements and compounds. The oceans became a ‘magma soup’ of complex molecules that eventually formed into proteins. Over millions of years of evolution, these proteins gave rise to all life as we know it today, including even ourselves.
The Bond Between Shirasu and Humans
Since shirasu is a special soil that is born from magma, it can be said that magma itself is a distant ancestor of shirasu, and therefore also of humans, who share a deep, longstanding, living bond with the soil.