Limonite pseudomorph

Example 7.7. Development of a limonite pseudomorph after pyrite... 

PSEUDOMORPH. In mineralogy and geology, a mineral, having the crystal form of one species and the chemical composition of another. Typical pseudomorphs are malachite in the form of cuprite, barite in the form of quartz, limonite in the form of pyrite. In such cases of pseudomorphism the evidence seems to be that there has been a complete chemical and molecular change but without any change of the original outward form. See also Mineralogy. 

The goethite pseudomorph is an easy one—the original pyrite is in the isometric system. Incidentally, these particular pseudomorphs are sometimes referred to as limonite. The term limonite is not an accepted mineral name and is used when the composition of the iron oxide is uncertain. The names of minerals are... 

BM 1929,1830 Pale yellow, powdery pseudomorphs with malachite in limonite. Jessie mine, 120 miles S.E. of Kabwe, Zambia. 

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See also in sourсe #XX -- [ ]

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