Mooihoekite to chalcopyrite CuFeS, making it helpful in the study of ore deposits and the study of the central portion of the Cu-Fe-S phase system. Mooihoekite, chalcopyrite, talnakhite, and haycockite all play key roles in the study of ore genesis and beneficiation. Mooihoekite Mooihoekite is a copper iron sulfide mineral with chemical formula of CuFeS. The mineral was discovered in 1972 and received its name from its discovery area, the Mooihoek mine in Transvaal, South Africa. Mooihoekite crystallizes in the tetragonal crystal system. It has a short optical c-axis that is perpendicular to two longer a-axes of equal length. For Mooihoekite,
Ore Mountains this is a contract between Boresch of Riesenburg and the Ossegg abbot, Gerwig, in which the division of revenue derived from ore was agreed. Grains of tin ("Zinnkörner" or "Graupen") were obtained at that time in the Seiffen mining area and gave the Bohemian mining town of Graupen (Czech "Krupka") its name. With the further settlement of the Ore Mountains in the 15th century, new, rich, ore deposits were eventually discovered around Schneeberg Annaberg and St. Joachimsthal. The "Second Berggeschrey" started and triggered a massive wave of colonization. In quick succession, new, planned, mining towns were built across the Ore