Koasite

Koasite is a mineral, a type of silicate, with the chemical formula Mg3Si2O5(OH)4. It is a member of the serpentine group of minerals, which are characterized by their layered silicate structure. Koasite is found in serpentinized ultramafic rocks, often as a secondary mineral formed by the alteration of olivine or pyroxene. Its appearance is typically greenish, ranging from pale green to dark green, and it often occurs in fibrous or platy aggregates. The mineral is known for its relatively low hardness, making it somewhat soft and easily scratched. Koasite can also be found in association with other serpentine minerals like lizardite and chrysotile. Its formation is generally linked to hydrothermal alteration processes under low-grade metamorphic conditions. While not economically significant for large-scale mining, koasite can be of interest to geologists studying metamorphic petrology and the alteration of oceanic crust. Its properties, such as its color and texture, contribute to the overall appearance of the rocks in which it is found.