kufirit

Kufirit is a rare copper-iron sulfide mineral that occurs as metallic to submetallic crystals and aggregates. It displays a bronze to steel-gray color with a metallic luster, and its streak is typically dark gray to coppery. The mineral is opaque and has a Mohs hardness around 3 to 4. Crystals are commonly prismatic or tabular, though well-formed euhedral forms are uncommon.

Chemically, kufirit consists mainly of copper and iron with sulfur as the anion, and it shows limited solid-solution with nickel and cobalt in some samples. The precise formula can vary within a restricted range, and impurities influence color and luster. Kufirit is classified within the sulfide mineral group.

Kufirit forms in hydrothermal ore veins and is typically associated with chalcopyrite, pyrite, and sphalerite, in low- to medium-temperature environments. Occurrences have been reported in regions with volcanic-sedimentary rocks and in contact metamorphosed zones, where hydrothermal fluids mobilize copper and iron.

The mineral was named kufirit after the region where it was first identified, following standard mineralogical naming conventions with the -ite suffix. Descriptions and analyses published in field reports and mineralogical literature established its characteristic properties and associations.

Because kufirit is rare, it is not a primary ore but is of interest to mineral collectors and researchers studying sulfide mineralization. It can serve as an indicator mineral in exploration for copper-rich ore deposits in settings with compatible hydrothermal activity, and it contributes to the understanding of copper-iron sulfide chemistry in hydrothermal systems.