Chalcopyrite is closely related to that of zinc blende ZnS (sphalerite). The unit cell is twice as large, reflecting an alternation of Cu and Fe ions replacing Zn ions in adjacent cells. In contrast to the pyrite structure chalcopyrite has single S sulfide anions rather than disulfide pairs. Another difference is that the iron cation is not diamagnetic low spin Fe(II) as in pyrite. Copper metal can be extracted from the roasting of chalcopyrite, as shown in the following reaction: Although if roasted partially it produces and . Chalcopyrite Chalcopyrite ( ) is a copper iron sulfide mineral that crystallizes in
Carbonate-hosted lead-zinc ore deposits brines (10-30 wt.% NaCl equivalent) with pH's of 4.5-5 (buffered by host carbonates). This hydrothermal fluid may or may not carry the required sulfur to form sulfide minerals. Mobile hydrocarbons may have played a role in delivering reduced sulfur to certain MVT systems, while methane and other organic matter can potentially reduce sulfate carried by an acidic fluid. The ore fluid is suspected to be derived from clastic red bed sequences (potential metal source) that contain evaporites (potential sulfur source). Two potential transportation mechanisms for the metal-bearing ore fluid have been proposed. The first involves compaction of sediments in basins