Oregonite
Oregonite is a copper, iron, zinc sulfide mineral with the chemical formula CuFeZn2S4. It is a rare member of the stannite group and is typically found in massive form with a metallic luster and a dark grey to black color.
Discovery and Occurrence:
Oregonite was first described in 1978 by F. Klockmann for an occurrence in the Nickel Plate mine, Riddle, Douglas County, Oregon, USA, which is also its type locality. It's typically found in hydrothermal veins and associated with other sulfide minerals. While named after Oregon, it has since been identified in other locations, albeit rarely.
Physical Properties:
Oregonite is opaque with a metallic luster. Its streak is black. Its hardness varies, but it is generally described as being moderately soft. It lacks distinct cleavage. It is weakly magnetic.
Chemical Properties:
Oregonite is a sulfide mineral containing copper, iron, zinc, and sulfur. The relative proportions of these elements are crucial to its identification, as its composition is reflected in its chemical formula CuFeZn2S4.
Identification:
Due to its rarity and massive form, positive identification of Oregonite usually requires X-ray diffraction analysis or other advanced analytical techniques. Its association with other sulfide minerals, along with its physical properties, can provide clues to its presence.