Mineralization consists principally of pyrrhotite, pyrite, pentlandite (violarite
) and chalcopyrite; the zone is sub-vertical and arcuate in plan.
The Tynebottom mine has produced an interesting suite of nickel and cobalt-containing minerals including erythrite, safflorite, nickel-skullerudite, violarite
, rammelsbergite, annabergite, and some very attractive specimens of drusy calcite and "flowstone" colored pink to deep magenta by micro-inclusions of erythrite, or blue by copper salts.
The results of X-ray diffraction (XRD) analysis reveal the presence of chalcopyrite (CuFe[S.sub.2]), pentlandite [[(Fe Ni).sub.9] [S.sub.8]] as major phases and pyrite (Fe[S.sub.2]), pyrrhotite (FeS), violarite
[[(Ni Fe).sub.3] [S.sub.4]] as minor phases in the copper flotation concentrate prior to leaching(Table.3).
Traces of violarite
, sphalerite, galena, marcasite, arsenopyrite, and bravoite have also been noted.
The oxidation of a violarite
and pyrite-containing nickel concentrate from the Forrestania mine in Western Australia has been studied(4).
Less well known, however, are the minerals that have been exposed in limestone quarries in west-central Illinois, including display-quality specimens of twinned calcite and the uncommon minerals violarite
Maiwan & other small mines) Xiangtan Hunan manganite Xiaojie Sichuan amazonite, quartz Xiaosongshan Ningxia diopside Xikuangshan Hunan barite, calcite, cervantite, fluorite, gypsum, pyrite, quartz, senarmontite, stibiconite, stibnite, sulfur, valentinite Xinzai Yunnan cassiterite Xiongxiong' Guizhou hematite, "limonite," siderite ga Xixia Henan andalusite Xiyugou Liaoning antigorite, chlorite, chrysotile, lizardite, talc, tremolite Xuebaoding Sichuan apatite, aquamarine, cassiterite, (Hujia) dolomite, feldspar, fluorite, goshenite, morganite, muscovite, quartz, scheelite Yangliuping Sichuan bornite, chromium, *danbaite, gold, linnaeite, sperrylite, testiobiopallasite, violarite
Yangshuo Guangxi, calcite, cerussite, pyromorphite Zhuang A.R.
Occurrence: (1) In an altered gabbronorite associated mainly with chalcopyrite, pentlandite, violarite
, actinolite and clinochlore; several other PGM species also occur here.
The X-ray powder pattern is very similar to that of violarite
There are several unusual associations with millerite which are summarized here: apparent nucleation around chalcopyrite and sphalerite; impaled or suspended calcite, chalcopyrite, gypsum and pyrite; coatings of late-formed microscopic quartz; the alteration to a possible nickel sulfate; and violarite
chalcopyrite, pentlandite, pyrite, cobaltite-gersdorffite series, arsenopyrite, ullmannite, violarite
, chromite, ilmenite, sphalerite, covellite, argentopentlandite, breithauptite, marcasite, nickeline, galena, rutile, barite, hessite, Au-Ag alloys, sperrylite, moncheite, sudburyite, testibiopalladite, kotulskite, mertieite-II, stibiopalladinite, geversite, melonite and four undefined minerals.
The lowermost portion of the zone is marked by the appearance of minor amounts (0.5-2%) of smythite and violarite
(Table 1) which are typically more abundant in massive sulfides than in the matrix and disseminated sulfides.