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
Precious metal coinage. Other precious metals include the platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum, of which platinum is the most widely traded. The demand for precious metals is driven not only by their practical use but also by their role as investments and a store of value. Historically, precious metals have commanded much higher prices than common industrial metals. A metal is deemed to be "precious" if it is rare. The discovery of new sources of ore or improvements in mining or refining processes may cause the value of a precious metal to diminish. The status of a