Goldichite of fumarolic origin from Santa Bárbara Mine, Northwestern Argentine.

MÁRQUEZ ZAVALÍA, M. F., Y GALLISKI, M. A.,

CANADIAN MINERALOGIST

Mineralogical Association of Canada

Lugar: Ottawa; Año: 1995 vol. 33 p. 1059 - 1062

0008-4476

The fust find of goldichite in Argentinaa ndt he third world-wide occurrenceis describedT. he mineral was found in a sulfurdeposit,t he SantaB irbara mine, in iujuy province,f ormed by present-daya ctivity of thermal springs.T he Tioeral occursw ithmetavoltine,h exahydrite,a lunogen,s ideronatritef,e ninatrite, voltaite, kausite, halotrichite,g ypsuma nd halite. The goldichite@cursa se uhedrafll attened"ryitatsO.: -- in lenglh,t abularo n { 100}, with t 100}, { 110} and {011} crystallographifco rms.The strongestf ive X-ray powder-diffractionh nJs ld in A(t)(hkt)l are: 10.11(70)(100)5,. 11(40X200)3, .072(100)Q02),2.444A0h30. and2 .283i30e33). The refined unir-cell parameters6 f 1[is 6sn6rslinic mineral arc a 10.397Q),b 10.461(8),c g.tog<qjA , $ rOO.Ootll;,V 972.5(8)A ,3T. he crystalsa ret ransparenbt,r ittle, andh avea greenishh ue in naturallighta ndapale pink´tint onOeru ttinaa nght; Oreyh ave a hardnesso f 2-3, n excellent { 100} cleavage,v itreous luster and white streak.OptiJuUVg, oldichite is traasparint,w iih positive elongation,w ith X colorless,I colorlesst o very pale yellow, anjlZ very paley"no*: i j v > x:biaxial (+), 2vbd.=;,cl 1.584(2)F, 1.602Q),y1 ,.634Q),X= b, Y´a, Z lt c 9o,v > r, sfong´ The chemicalcomposition,o btainedb y electrotil-microprobaen alysii, indicatesS , Fe and K as the principal compon€ntsw, rJLthe^followingranges in concentrationo f the oxidei (w.%o): P2O50 .80-1.02, Sq 52.39-57.19,T iO2 0.84´n, A12O30 .02-0.16,CaO0 .01-O.05F, qO, 28.57-30.26N, a2O0 .294.46, andK 2O8 .81-9.82.Keywords: goldichite, funaxole, Santa Bdrbara mine, Jujuy province, Argentina.