Goldmanite from the Black Slates of the Ogcheon Belt, Korea

G. Y. Jeong and Y. H. Kim
Department of Earth and Environmental Sciences, Andong National University, Andong 760-749, Korea

Abstract: Goldmanite, the vanadium analogue of grossular and andradite, was found as subrounded green porphyroblasts ranging from 0.1 to 1.7 mm in size in the carbonaceous black slates from the Deokpyeong area of the Ogcheon belt in Korea. A radiating aggregate of slightly curved blades of goldmanite crystals displays birefringence and replaces the fine-grained black matrix. The V2O3 content ranges from 21.9 to 26.6 wt.% (24.0 wt.% average), higher than previously reported values. The calculated mole % of the goldmanite end-member ranges from 72 to 91. Its cell dimension was calculated to be 12.04 Å from X-ray diffraction. The black slate in the Deokpyeong area is the richest known accessible source of relatively pure goldmanite.

Keywords: black slate • garnet • goldmanite • vanadium

Mineralogical Magazine; April 1999 v. 63; no. 2; p. 253-256; DOI: 10.1180/002646199548358
© 1999, The Mineralogical Society
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