What is "esseneite"

n. (context mineral English) A monoclinic-prismatic reddish brown mineral containing aluminum, calcium, iron, oxygen, and silicon.

Esseneite is a relative rare mineral of the pyroxene group, with formula CaFeAlSiO. It is the ferric- iron-dominant member. Esseneite is an iron-analogue of other pyroxene-group members, davisite, grossmanite, and kushiroite. It is a metamorphic mineral forming in pyrometamorphic rocks called paralavas, which are formed due to fusing on sedimentary rocks usually in result of coal fires. Esseneite is found in both natural and anthropogenic coal-fire sites.