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@article{1317027,
author = {Čopjaková, Renata and Škoda, Radek and Vašinová Galiová, Michaela and Novák, Milan and Cempírek, Jan},
article_location = {CHANTILLY},
article_number = {7},
keywords = {Schorl; fluor-elbaite; tourmaline replacement; Sc-rich REE-bearing epidote-group mineral; granitic pegmatite; Bohemian Massif},
language = {eng},
issn = {0003-004X},
journal = {American Mineralogist},
title = {Sc- and REE-rich tourmaline replaced by Sc-rich REE-bearing epidote-group mineral from the mixed (NYF plus LCT) Kracovice pegmatite (Moldanubian Zone, Czech Republic)},
volume = {100},
year = {2015}
}
TY - JOUR
ID - 1317027
AU - Čopjaková, Renata - Škoda, Radek - Vašinová Galiová, Michaela - Novák, Milan - Cempírek, Jan
PY - 2015
TI - Sc- and REE-rich tourmaline replaced by Sc-rich REE-bearing epidote-group mineral from the mixed (NYF plus LCT) Kracovice pegmatite (Moldanubian Zone, Czech Republic)
JF - American Mineralogist
VL - 100
IS - 7
SP - 1434-1451
EP - 1434-1451
PB - Mineralogical Society of America
SN - 0003004X
KW - Schorl
KW - fluor-elbaite
KW - tourmaline replacement
KW - Sc-rich REE-bearing epidote-group mineral
KW - granitic pegmatite
KW - Bohemian Massif
N2 - Primary black thick-prismatic Al-rich schorl to rare fluor-schorl (TurP1), locally overgrown by brownish-green Li-rich fluor-schorl to fluor-elbaite (TurP2) from the Kracovice pegmatite (mixed NYF+LCT signature), was partly replaced by secondary Li-rich fluor-schorl to fluor-elbaite (TurS) plus the assemblage REE-bearing epidote-group mineral + chamosite. Primary Al-rich schorl (TurP1) shows high and variable contents of Sc (33-364 ppm) and Y+REE (40-458 ppm) with steep, LREE-enriched REE pattern. Overgrowing (TurP2) and replacing (TurS) Li-rich fluor-schorl to fluor-elbaite is typically depleted in Sc (21-60 ppm) and Y+REE (3-47 ppm) with well-developed tetrad effect in the first (La-Nd) and the second (Sm-Gd) tetrads. Scandium- and REE-rich black tourmaline (TurP1) crystallized earlier from the melt, whereas crystallization of primary Li-rich fluor-schorl to fluor-elbaite (TurP2) most likely took place during late magmatic to early hydrothermal conditions. Both the secondary Li-rich fluor-schorl to fluor-elbaite (TurS) and the unusual assemblage of REE-bearing epidote-group mineral + chamosite are likely coeval products of subsolidus reactions of the magmatic Al-rich schorl (TurP1) with evolved REE-poor, Li,F-rich, alkaline pegmatite-derived fluids. Well-crystalline REE-bearing epidote-group mineral (Y+REE = 0.42-0.60 apfu) confirmed by Raman spectroscopy has a steep, LREE-rich chondrite-normalized REE pattern with significant negative Eu anomaly and shows variable and high contents of Sc (<= 3.3 wt% Sc2O3) and Sn (<= 1.0 wt% SnO2). Substitution ScAl-1, and minor vacancy in the octahedral sites are suggested in the REE-bearing epidote-group mineral.
ER -
ČOPJAKOVÁ, Renata, Radek ŠKODA, Michaela VAŠINOVÁ GALIOVÁ, Milan NOVÁK a Jan CEMPÍREK. Sc- and REE-rich tourmaline replaced by Sc-rich REE-bearing epidote-group mineral from the mixed (NYF plus LCT) Kracovice pegmatite (Moldanubian Zone, Czech Republic). \textit{American Mineralogist}. CHANTILLY: Mineralogical Society of America, 2015, roč.~100, č.~7, s.~1434-1451. ISSN~0003-004X.
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