Perlitikivi

Perlitikivi is a Finnish term referring to a type of rock that contains perlite. Perlite itself is a naturally occurring volcanic glass that forms when rhyolite lava cools rapidly. Its unique characteristic is its ability to expand significantly when heated. This expansion is due to the presence of water within the perlite. When perlite is heated to around 850-900 degrees Celsius, the water rapidly turns to steam, causing the glass to expand and form a lightweight, cellular material.

Perlitikivi is essentially a deposit of this perlite-rich volcanic rock. These deposits are found in areas with past volcanic activity. The rock itself, before expansion, might appear as a glassy, often grey or white, material with a conchoidal fracture. The presence of perlite within the rock is what gives it its potential economic value.

The primary use of perlite, and therefore perlitikivi as a source material, is after it has been processed and expanded. Expanded perlite has a very low density, is chemically inert, non-combustible, and has excellent insulating properties. These characteristics make it useful in a wide range of applications. It is commonly used in horticulture as a soil amendment to improve drainage and aeration, in construction as an aggregate for lightweight concrete and insulating boards, and as a filter aid in various industries. The extraction and processing of perlitikivi are therefore important for supplying these diverse markets.