The Origin of Accessory Garnet in the Donegal Granite

Anthony Hall and Miss R. C. Tyler
Geology Department, King's College, London WC. 2

Summary: In the Donegal Granite garnet occurs as an accessory mineral in muscovite-granties, pegmatites, and aplites. The composition of the garnet in fourteen samples of granitic rock has been determined from the physical properties and three new chemical analyses are given. All the samples examined are intermediate in composition between almandine and spessartine. The reason for the high manganese content in garnet from granites is discussed.

Mineralogical Magazine; December 1965 v. 35; no. 272; p. 628-633; DOI: 10.1180/minmag.1965.035.272.06
© 1965, The Mineralogical Society
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