(redirected from pyritical)
Also found in: Dictionary, Thesaurus.


(pī`rīt) or

iron pyrites

(pīrī`tēz, pə–, pī`rīts), pale brass-yellow mineral, the bisulfide of iron, FeS2. It occurs most commonly in crystals (belonging to the isometric system and usually in the form of cubes and pyritohedrons) but is also found in massive, granular, and stalactite form. In spite of its nickname, "fool's gold," it often is associated with true gold; auriferous pyrite is a commercially important source of gold. Other metals that sometimes replace a part of the iron are cobalt, nickel, arsenic, and copper. The most common sulfide mineral, pyrite is widely distributed in rocks of all ages and types. Its chief use is as a source of sulfur in the manufacture of sulfuric acid. The term pyrites is applied to any of a number of metallic sulfides that strike fire with steel. Some minerals resembling pyrite in appearance or composition are arsenopyritearsenopyrite
or mispickel
, silver-white to steel-gray mineral with the metallic luster characteristic of a pyrite. It is a sulfarsenide of iron, FeAsS, crystallizing in the orthorhombic system and occurring also in massive form.
..... Click the link for more information.
, chalcopyritechalcopyrite
or copper pyrites
, brass-yellow mineral, sometimes with an iridescent tarnish. It is a sulfide of copper and iron, CuFeS2 . It crystallizes in the tetragonal system but is usually found in the massive form.
..... Click the link for more information.
 (copper pyrites), cobaltitecobaltite
, opaque, silver-white, sometimes reddish or grayish mineral of the pyrite group, a compound of cobalt, arsenic, and sulfur, CoAsS. It occurs in crystals of the cubic system, also in compact to granular masses.
..... Click the link for more information.
, marcasitemarcasite
or white iron pyrites,
a mineral closely resembling and having the same chemical composition (FeS2) as pyrite. It differs from pyrite in that it is paler in color, becomes darker upon oxidation, and crystallizes in the orthorhombic system.
..... Click the link for more information.
 (white iron pyrites or spear pyrites), and pyrrhotitepyrrhotite
or magnetic pyrites,
bronze-yellow to bronze-red mineral, a sulfide of iron sometimes containing nickel. It tarnishes easily and is somewhat magnetic.
..... Click the link for more information.
 (magnetic pyrites).
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



(also iron pyrite), a mineral with the chemical composition FeS2, containing 46.6 percent iron and 53.4 percent sulfur. Admixtures of Co, Ni, As, Cu, Au, and Se are common. The crystal structure is of the NaCl type, in which Fe occupies the position of Na, and the dumbbell-like S22- pair, that of CI. Pyrite crystallizes in the isometric system, forming cubic, pyri-tohedral, and, less often, octahedral crystals. Most often it is massive or granular. It has a pale brass-yellow color and a metallic luster. Its hardness on Mohs’ scale is 6–6.5, and the density ranges from 4,900 to 5,200 kg/m3.

Pyrite is most widely distributed in hydrothermal deposits and in pyrite veins, in which large amounts of the mineral are concentrated. It serves as the raw material for the production of sulfuric acid, sulfur, and copperas (ferrous sulfate). Pyrite deposits in the USSR are found in the Ural Mountains (Degtiarka and Kalata deposits), the Altai, Kazakhstan, and Transcaucasia. Deposits are also found in Norway, Spain (Rio Tinto), Italy, Cyprus, USA, Canada, and Japan.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


FeS2 A hard, brittle, brass-yellow mineral with metallic luster, crystallizing in the isometric system; hardness is 6-6.5 on Mohs scale, and specific gravity is 5.02. Also known as common pyrite; fool's gold; iron pyrites; mundic.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


a yellow mineral, found in igneous and metamorphic rocks and in veins. It is a source of sulphur and is used in the manufacture of sulphuric acid. Composition: iron sulphide. Formula: FeS2. Crystal structure: cubic
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005