Goodchild, of the Scottish Geological Survey, found wulfenite there in 1875 but the locality only really became of interest to collectors in the 1950s following the reporting of a suite of rare supergene minerals including bayldonite, duftite, beudantite, carminite, lindgrenite
and stolzite (the first authenticated British occurrence).
Extensive collecting at the abandoned mines has revealed over 65 mineral species in a complex polymetallic quartz vein system, including bismutoferrite, bismutostibiconite, clinobisvanite, koechlinite, namibite, schumacherite, posnjakite, wroewolfeite, idaite, cornwallite, clinoclase, cornubite and lindgrenite
In January 1993 Terry and Marissa Szenics of Santiago collected a beautiful green mineral, thought to be lindgrenite, at a small copper mine in northern Chile and through the Aurora Mineral Corporation submitted it to the Harvard Mineralogical Museum for identification.
1 mine lindgrenite was made when the szenicsite samples were reground and its Al content is at the detection limit of 0.016 wt.% [Al.sub.2][O.sub.3].
Szenicsite joins ferrimolybdite, lindgrenite, powellite and wulfenite as a simple molybdate.
Infrared spectra of both szenicsite and type lindgrenite were recorded from single crystals mounted in a diamond cell on a Spectra Tech IR-Plan microscope attached to a Nicolet 510 FT-IR spectrometer by Eugene Farrell at the Harvard University Art Museums.
Infrared spectra of szenicsite and lindgrenite. Szenicsite Lindgrenite Position Height Position Height 3559 m 3526 m 3524 s 3420 m, shoulder 3505 s 3347 m 2409 w, broad 1633 w, broad 1089 w 942 m 900 shoulder 795 vs 834 vs 690 shoulder 650 shoulder 625 m m medium, s strong, vs very strong, w weak
Significantly, lindgrenite with its lower Cu:Mo ratio of 3:2 is known to have a framework structure (Hawthorne & Eby, 1985).
Barite, brochantite, chalcocite, chalcopyrite, gold, hematite, lindgrenite and molybdenite-2H have also been identified in the specimen suite.
Lindgrenite occurs sparingly as seams in a white, altered rock in a zone beyond the szenicsite.
Lindgrenite, [Cu.sub.3][(Mo[O.sub.4]).sub.2][(OH).sub.2], is well known at Chuquicamata, the type locality about 500 km north of Inca de Oro, so lindgrenite was a logical provisional identification when the szenicsite was first found; a comparison of their properties, however, shows them to be distinctly different.