24 - Phyliite

Hello friends, Welcome to the Rock Repository at the Department of Geology, Shivaji Science College, Nagpur.

I am Phyllite, a type of foliated metamorphic rock that forms under relatively low grade metamorphic conditions, typically between slate and schist in terms of metamorphic grade. I am formed from the metamorphism of slate due to high temperature and pressure causing recrystallization of minerals and development of foliation. My most characteristic feature is my tendency to exhibit a sheen or a luster due to the alignment of constituent mineral grains. I am primarily composed of mica minerals such as muscovite and biotite as well as quartz and sometimes chlorite. These minerals contribute to my sheen and luster. I am mostly found in shades of gray, green or black colors but depending on the mineral composition, the color varies. I exhibit a well-developed foliation due to preferred orientation of constituent mineral grains. The foliation is typically less pronounced compared to gneiss or schist, but is still visible to the naked eye. I also show excellent fissility (a tendency to split into sheets). I am a soft and durable rock and hence I am used in floor tiles, interior home decorations, and garden decorations. I am also used in the construction industry. Thank you for visiting.