Giustino, "GW quasiparticle band structures of stibnite, antimonselite, bismuthinite
, and guanajuatite," Physical Review B, vol.
Elevated Bi content in till (10s of ppm) is likely hosted in the Bi-rich minerals native bismuth (Bi), bismuthinite
([Bi.sub.2]S3), bismutite ([Bi.sub.2](C[O.sub.2])[O.sub.2]), and joseite (Bi4(S,Te)3) that were recovered from the heavy mineral fraction of metal-rich till samples overlying and up to 4 km down ice (southeast) of the deposit (McClenaghan et al.
against a black background, is a kingly crocoite specimen; on the back cover we make the pictorial acquaintance of bismuthinite
, cassiterite, fluorite and siderite from little-known Tasmanian places.
Sulfide minerals in the quartz veins are much more varied than in replacement ores; pyrite masses in the former contain up to 2% arsenopyrite and trace to minor amounts of galena, sphalerite, scheelite, pyrrhotite, chalcopyrite, cosalite and bismuthinite
. The latter two minerals are important because they occur with fine visible gold and quartz crystals in drusy vugs.
Mineralization is characterized by sugary textured quartz veins and locally vein stockworks of variable orientations associated with intrusive and country rock (gneisses) containing trace to 2 percent sulfides characterized by arsenopyrite +/- bismuthinite
+/- molybdenite and, locally, visible gold.
The other main sulphide minerals are chalcopyrite, sphalerite, galena, tennanite, bismuthinite
The specimen photos, by about 25 people, are predictably excellent; many, of course, have been published before, but who can complain about seeing, all over again, such magnificent things as the 3.6-cm Oruro andorite/stannite on page 26; the 9.2-cm Tasna bismuthinite
on page 45; the 3.1-cm spherical Llallagua vauxite on page 50; the thumbnail-size Colquechaca canfieldite on page 67; the surprising 8.2-cm Corocoro copper on page 79; the stunning cassiterites, ferberites, wavellites and apatites on several pages; and of course the great phosphophyl-lites, including Andy Seibel's breathtaking 5.2-cm matrix specimen on the front cover?
Felsic units are from 1 foot to 10 feet thick and well-mineralized with pyrite, pyrrhotite and bismuthinite
in carbonate-altered quartz veins and veinlets and as disseminated grains.
Bismuth is present as free grains or in a mymerkitic intergrowth with gold; bismuthinite
([Bi.sub.2] [S.sub.3]), galenobismutite (Pb [Bi.sub.2] [S.sub.4]) and tellurobismutite are also fund.
The pseudocrystals are up to about 1 cm long, and grow on white barite together with acicular crystals of bismuthinite
The most spectacular find of all, however, surfaced in early 2002 when two mineral dealers in Changsha offered long, thin, reddish crystals intergrown in radiating groups, identifying them as "bismuthinite
"--the name commonly applied there to any thin or acicular crystals from Yaogangaxian.
The first depositional stage of the veins is represented by quartz, tourmaline, bismuthinite
and cassiterite, with minor wolframite and fluorapatite.