sulfide mineral

sulfide mineral
or sulphide mineral

Any member of a group of compounds of sulfur with one or more metals.

The metals that occur most commonly are iron, copper, nickel, lead, cobalt, silver, and zinc. They are the ore minerals of most metals used by industry (e.g., antimony, bismuth, copper, lead, nickel, and zinc). Other industrially important metals such as cadmium and selenium occur in trace amounts in numerous common sulfides and are recovered in refining processes.

Pyrite from Butte, Mont.

By courtesy of (centre) Joseph and Helen Guetterman Collection; photographs, John H. Gerard

* * *

sulfide also spelled  Sulphide,  

      any member of a group of compounds of sulfur with one or more metals. Most of the sulfides are simple structurally, exhibit high symmetry in their crystal forms, and have many of the properties of metals, including metallic lustre and electrical conductivity. They often are strikingly coloured and have a low hardness and a high specific gravity.

      The composition of the sulfide minerals can be expressed with the general chemical formula AmSn, in which A is a metal, S is sulfur, and m and n are integers, giving A2S, AS, A3S4 and AS2 stoichiometries. The metals that occur most commonly in sulfides are iron, copper, nickel, lead, cobalt, silver, and zinc, though about fifteen others enter sulfide structures.

      Almost all sulfide minerals have structural arrangements that belong to six basic types, four of which are important. These arrangements are close-packing combinations of metal and sulfur, governed by ionic size and charge.

      The simplest and most symmetrical of the four important structural types is the sodium chloride structure, in which each ion occupies a position within an octahedron consisting of six oppositely charged neighbours. The most common sulfide crystalling in this manner is galena (PbS), the ore mineral of lead. A type of packing that involves two sulfide ions in each of the octahedral positions in the sodium chloride structure is the pyrite structure. This is a high-symmetry structure characteristic of the iron sulfide, pyrite (FeS2O). The second distinct structural type is that of sphalerite (ZnS), in which each metal ion is surrounded by six oppositely charged ions arranged tetrahedrally. The third significant structural type is that of fluorite, in which the metal cation is surrounded by eight anions; each anion, in turn, is surrounded by four metal cations. The reverse of this structure—the metal cation surrounded by four anions and each anion surrounded by eight metal cations—is called the antifluorite structure. It is the arrangement of some of the more valuable precious metal tellurides and selenides among which is hessite (Ag2Te), the ore mineral of silver.

      In virtually all of the sulfides, bonding is covalent, but some have metallic properties. The covalent property of sulfur allows sulfur-sulfur bonds and the incorporation of S2 pairs in some sulfides such as pyrite. Several sulfides, including molybdenite (MoS2) and covellite (CuS), have layer structures. Several rare sulfide varieties have the spinel (q.v.) structure.

      Phase relations of sulfides are particularly complex, and many solid state reactions occur at relatively low temperatures (100–300° C [212–572° F]), producing complex intergrowths. Particular emphasis has been placed on the experimental investigation of the iron-nickel-copper sulfides because they are by far the most common. They also are important geologic indicators for locating possible ore bodies and provide low-temperature reactions for geothermometry.

      Sulfides occur in all rock types. Except for dissemination in certain sedimentary rocks, these minerals tend to occur in isolated concentrations which make up mineral bodies such as veins and fracture fillings or which comprise replacements of preexisting rocks in the shape of blankets. Sulfide mineral deposits originate in two principal processes, both of which have reducing conditions: (1) separation of an immiscible sulfide melt during the early stages of crystallization of basic magmas; and (2) deposition from aqueous brine solutions at temperatures in the 300–600° C (572–1,112° F) range and at relatively high pressure, such as at the seafloor or several kilometres beneath Earth's surface. The sulfide deposits formed as a result of the first process include mainly pyrrhotites, pyrites, pentlandites, and chalcopyrites. Most others occur because of the latter process. Weathering may act to concentrate dispersed sulfides.

      Sulfide minerals are the source of various precious metals, most notably gold, silver, and platinum. They also are the ore minerals of most metals used by industry, as for example antimony, bismuth, copper, lead, nickel, and zinc. Other industrially important metals such as cadmium and selenium occur in trace amounts in numerous common sulfides and are recovered in refining processes.

       Sulfide mineralsFor the more common sulfide minerals and their physical properties, see the Table (Sulfide minerals).

* * *


Universalium. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Sulfide mineral — A sulfide mineral is a mineral containing sulfide (S2 ) as the major anion. Sulfides are economically important as metal ores. The sulfide class also includes the selenides, the tellurides, the arsenides, the antimonides, the bismuthinides, and… …   Wikipedia

  • Sulfide mining — a colloquial term used in Wisconsin, Michigan, and Minnesota to describe the act of mining of ore which contains significant quantities of sulfide minerals. Copper, lead, zinc, and nickel ores are typically present in the sulfide minerals… …   Wikipedia

  • mineral deposit — Introduction       aggregate of a mineral in an unusually high concentration.       About half of the known chemical elements (chemical element) possess some metallic (metal) properties. The term metal, however, is reserved for those chemical… …   Universalium

  • Sulfide — For other uses, see Sulphide (disambiguation). Sulfide Systematic name Sulfanediide …   Wikipedia

  • sulfide — /sul fuyd, fid/, n. Chem. a compound of sulfur with a more electropositive element or, less often, a group. [1830 40; SULF(UR) + IDE] * * * ▪ inorganic Introduction also spelled  sulphide    any of three classes of chemical compounds containing… …   Universalium

  • mineral — /min euhr euhl, min reuhl/, n. 1. any of a class of substances occurring in nature, usually comprising inorganic substances, as quartz or feldspar, of definite chemical composition and usually of definite crystal structure, but sometimes also… …   Universalium

  • mineral water — 1. water containing dissolved mineral salts or gases, esp. such water considered healthful to drink. 2. mineral waters, Brit. a. carbonated water; soda water. b. artificially flavored, bottled soft drinks; soda pop. [1555 65] * * *       water… …   Universalium

  • Mineral exploration — is the process of finding ore (commercially viable concentrations of minerals) to mine. Mineral exploration is a much more intensive, organized and professional form of mineral prospecting and, though it frequently uses the services of… …   Wikipedia

  • Mineral — For other uses, see Mineral (disambiguation). An assortment of minerals. A mineral is a naturally occurring …   Wikipedia

  • Sulfide — Das sulfidische Mineral Stibnit, eine chemische Verbindung von Antimon mit Schwefel Sulfide sind Salze beziehungsweise Alkyl oder Arylderivate des Schwefelwasserstoffs (H2S). Die Salze gehören zur Stoffgruppe der Metall Schwefel Verbin …   Deutsch Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”