What is "ferroselite"

n. (context mineral English) An orthorhombic-dipyramidal mineral containing iron and selenium.

Orthorhombic ferroselite and its isometric polymorph dzharkenite are iron selenides of general formula FeSe precipitated under reducing conditions in anoxic environments. They are a source of selenium in the Rocky Mountains where selenium occurrence is associated with Upper Cretaceous shale deposits.

In the frame of safety assessment calculations made for deep disposal of high-level radioactive waste, ferroselite and dzharkenite are also considered in geochemical calculations as one of the mineral phases limiting the solubility of Selenium-79.