Secondary Minerals

minerals formed by the chemical disintegration or displacement of minerals evolved earlier. The formation of secondary minerals is common in nature, especially in the surface zones of the earth’s crust during the processes of hypergenesis, and is also linked to changes in the physicochemical parameters of mineral formation.

The transition into secondary minerals can occur without a change in the quality of the composition of the substance— for example, the transition of chalcopyrite CuFeS₂ into the secondary bornite CuFeS₄. More frequently, however, transition is accompanied by the removal and exchange of substance from the surrounding medium—for instance, the formation of covellite Cu₂S CuS₂ through chalcopyrite, malachite Cu₂[CO₃](OH)₂ through atacamite CuCl₂ 3Cu (OH)₂, and kaolin through feldspar. Secondary minerals can also be formed during a purely physical change in the crystalline structure of a substance, retaining its chemical composition: cubic chalcosine changes to rhombic chalcosine, high-temperature cubic leucite changes to low-temperature rhombic leucite.

There are various forms of secondary minerals. These are powdery or other masses or pseudomorphs which retain the external form of the primary mineral while the substance is replaced by a new one.

REFERENCE

Lazarenko, E. K. Osnovy geneticheskoi mineralogii. L’vov, 1963.

G. P. BARSANOV

单词	secondary minerals
释义	Secondary Minerals Secondary Minerals minerals formed by the chemical disintegration or displacement of minerals evolved earlier. The formation of secondary minerals is common in nature, especially in the surface zones of the earth’s crust during the processes of hypergenesis, and is also linked to changes in the physicochemical parameters of mineral formation. The transition into secondary minerals can occur without a change in the quality of the composition of the substance— for example, the transition of chalcopyrite CuFeS₂ into the secondary bornite CuFeS₄. More frequently, however, transition is accompanied by the removal and exchange of substance from the surrounding medium—for instance, the formation of covellite Cu₂S CuS₂ through chalcopyrite, malachite Cu₂[CO₃](OH)₂ through atacamite CuCl₂ 3Cu (OH)₂, and kaolin through feldspar. Secondary minerals can also be formed during a purely physical change in the crystalline structure of a substance, retaining its chemical composition: cubic chalcosine changes to rhombic chalcosine, high-temperature cubic leucite changes to low-temperature rhombic leucite. There are various forms of secondary minerals. These are powdery or other masses or pseudomorphs which retain the external form of the primary mineral while the substance is replaced by a new one. REFERENCE Lazarenko, E. K. Osnovy geneticheskoi mineralogii. L’vov, 1963. G. P. BARSANOV
随便看	gone off their dot gone off their dots gone off their rocker gone off their rockers gone off the rails gone off the reservation gone off your dot gone off your rocker gone on gone on a binge gone on about gone on a diet gone on and on about gone on arrival gone one better gone on fire gone on for ages gone on for an age gone on leave gone on merry way gone on record gone on relief gone on strike gone on the block gone on the dole