The Structures of Sulfide Minerals

The sulfide minerals have structures based largely upon covalent bonds between the sulfur atoms and other atoms in the substances. In some of the minerals the bonds resonate among alternative positions, and in some there are also metal-metal bonds, conferring metallic properties, especially metallic luster, upon them. 

Galena, PbS, is an example of a mineral with metallic luster. The atoms are ordered in the sodium chloride arrangement. Each lead 

18 Other forms, corresponding to more complex arrangements of the tetrahedral layers, also occur in nature C. Frondel and C. Pal che, Am. Mineralogist 35, 29 (1950). 

—The structure of the crystal SiS2. Small circles represent silicon atoms, large circles sulfur atoms (Strukturbericht). 

Many sulfide minerals have structures closely related to those of sphalerite and wurtzite. Chalcopyrite, CuFeS, is an example (Fig. 11-21). Its structure 0 is a tetragonal superstructure of sphalerite, with the copper and iron atoms in the zinc positions of sphalerite. 

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