Dark sphalerite

The common sources of indium are the minerals dark sphalerite, christophite, and marmatite. Indium is also found in small amounts in manganese, tungsten, zinc, and tin ores. Rarely found as a free element, indium is commonly associated with gallium in tin and zinc ores. The main commercial source for indium is from zinc smelter flue dusts (Smith etal. 1977). Enrichment of indium from zinc residues is performed by acid leaching followed by chemical separation processes. Aqueous electrolysis of indium salts yields a final metal of 99.9% purity. Canada has the greatest resources of indium with approximately 27% of the world s reserves (based on estimated indium content of zinc reserves) and the United States has about 12% of the world reserves (Brown 2000). In recent years, there have been major improvements in the recovery, refining and recycling of... 

Structure of cubic (left) and hexagonal (right) diamond. Top row connected layers as in a-As. Central row the same layers in projection perpendicular to the layers. Bottom unit cells when the light and dark atoms are different, this corresponds to the structures of zinc blende (sphalerite) and wurtzite, respectively... 

A sphalerite dispersal train occurs in the centre of the study area (Fig. 2). Dark grey to black, brittle grains of sphalerite were found in high concentrations (>100 grains)... 

The optimal pH was ca. 3.5 (at lower values, the film was contaminated with elemental S, which forms spontaneously in the dark), while the deposition rate slowed down at higher values). The CdS was sphalerite, and, from an examination of the XRD, a crystal size of < 10 nm could be estimated. The bandgap was 2.42 eV, the hterature value for CdS. 

Similar ponds of metalliferous sediment are observed close to other inactive sulfide stmctures throughout the TAG area (Rona et al., 1993). Metz et al. (1988) characterized the metalliferous sediment in a core raised from a sediment pond close to one such deposit, 2 km NNE of the active TAG mound. That core consisted of alternating dark red-brown layers of weathered sulfide debris and fighter calcareous ooze. Traces of pyrite, chalcopyrite, and sphalerite, together with elevated transition-metal concentrations were found in the dark red-brown layers. 

Sulfur is found in meteorites. R.W. Wood suggests that the dark area near the crater Aristarchus is a sulfur deposit. Sulfur occurs naturally in the vicinity of volcanos and hot springs. It is widely distributed in nature as iron pyrites, galena, sphalerite, cinnabar, stibnite, gypsum, epsom salts, celestite, barite, etc. 

ABC. Notice that in Figure 43 there are six ions in the two middle layers, one in the top, and one in the bottom layer. The shading (darkness) of the bottom sphere shows that it is aligned with a sphere in the top layer. Hence, sphalerite is a face-centered, cubic closest-packed substance with the zinc cations located in the tetrahedral sites. 

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