Yaogangxian Mine, Yaogangxian W-Sn ore field, Yizhang Co., Chenzhou, Hunan, China (original) (raw)

Description: Some (all?) alleged bertrandite specimens from here were really from a different locality, many of them from the Liubao mine in Guangxi Province (although Berthold Ottens does not doubt the real occurrence of bertrandite at Yaogangxian).

ⓘ Beryl

Formula: Be3Al2(Si6O18)

ⓘ Beudantite

Formula: PbFe3(AsO4)(SO4)(OH)6

ⓘ 'Biotite'

Formula: K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2

References:

ⓘ Bismuthinite

Formula: Bi2S3

Description: Although bismuthinite has been reported in older references by Chinese authors, alleged silvery fibrous and acicular "bismuthinites" from here usually turn out to be stibnite on analysis (Jensen, 2009). Antimonian bismuthinite was found by Bart Cannon Microprobe Company on a Saul Krotki specimen.

ⓘ Bismutite ?

Formula: (BiO)2CO3

Description: Probably mis-identified and actually an alteration product of stibnite. Considering that Jensen (2009) could not confirm any independent bismuth minerals on contemporary specimens, the presence of bismutite appears very doubtful.

ⓘ Bornite ?

Formula: Cu5FeS4

Description: Perhaps a mistaken ID of blue-tarnished sphalerite (Jensen, 2009)

✪ Boulangerite

Formula: Pb5Sb4S11

Habit: Acicular fibrous crystals to 12 cm

Colour: Metallic silvery gray

Fluorescence: Not fluorescent

Description: Boulangerite is much rarer here than collectors think, with many alleged "boulangerite" specimens being stibnite (Jensen, 2009).

✪ Bournonite

Formula: PbCuSbS3

Habit: Large cogwheel twins to 2 cm

Colour: grey

Fluorescence: none

Description: Lacking the mirror brilliance of English bournonites, these bournonites are quite bright and certainly world class.

ⓘ Brochantite

Formula: Cu4(SO4)(OH)6

ⓘ Calcite

Formula: CaCO3

References:

ⓘ Calcite var. Argentine

Formula: CaCO3

ⓘ Calcite var. Manganese-bearing Calcite

Formula: (Ca,Mn)CO3

ⓘ Cassiterite

Formula: SnO2

References:

ⓘ Chalcopyrite

Formula: CuFeS2

References:

ⓘ Chamosite

Formula: (Fe2+)5Al(Si,Al)4O10(OH,O)8

ⓘ Clinochlore

Formula: Mg5Al(AlSi3O10)(OH)8

ⓘ Cookeite ?

Formula: (LiAl4◻)[AlSi3O10](OH)8

ⓘ Cosalite

Formula: Pb2Bi2S5

ⓘ Diopside

Formula: CaMgSi2O6

ⓘ Dolomite

Formula: CaMg(CO3)2

ⓘ Dyscrasite

Formula: Ag3Sb

ⓘ Epidote

Formula: (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)

ⓘ Euclase

Formula: BeAl(SiO4)(OH)

ⓘ 'Fayalite-Forsterite Series'

Description: Reported from the skarn ore bodies.

ⓘ Ferberite

Formula: FeWO4

ⓘ 'Ferberite-Hübnerite Series'

ⓘ Ferrokësterite

Formula: Cu2FeSnS4

ⓘ Fluorapatite

Formula: Ca5(PO4)3F

ⓘ Fluorite

Formula: CaF2

ⓘ 'Freibergite Subgroup'

Formula: (Ag6,[Ag6]4+)(Cu4 C2+2)Sb4S12S0-1

Description: According to Zhou (1994), argentian tetrahedrite is much more abundant at this locality than real freibergite. This is confirmed by analyses of traded "freibergite" specimens, which have mostly shown argentian tetrahedrite.

ⓘ Galena

Formula: PbS

References:

ⓘ Galenobismutite

Formula: PbBi2S4

Description: This mineral has been reported from the vein-type ore bodies (Chen, 1981). However, all traded specimens of alleged silvery fibrous and acicular "galenobismutite" that have so far been analyzed turned out to be stibnite or one of the sulfosalts. According to Jensen (2009), analyses of a large number of samples from all levels of the mine never disclosed the presence of any bismuth bearing minerals. These findings do not necessarily discredit all earlier reports, since it has to be kept in mind that all parts of the deposit were mined long before the first specimens appeared on the western market in the early 1990s, that mineralization zoning is a common phenomenon in intrusion-related deposits, and thus a different mineral assemblage may have been found in parts that are now mined out. They indicate however, that bismuth minerals are rare at this locality, if they can still be found at all.

ⓘ Goethite

Formula: α-Fe3+O(OH)

ⓘ Grossular

Formula: Ca3Al2(SiO4)3

ⓘ Gustavite

Formula: AgPbBi3S6

ⓘ Gypsum

Formula: CaSO4 · 2H2O

ⓘ Helvine

Formula: Be3Mn2+4(SiO4)3S

ⓘ Hessite

Formula: Ag2Te

ⓘ Hübnerite

Formula: MnWO4

Description: Data presented by Chen (1981) show a significant excess of manganese over iron (Fe:Mn ranging from 1:4 to 3:4) in all analyzed samples of wolframite from the vein-type ore bodies. Likewise, the samples from the quartz vein ore bodies used in the study by Cao et al. (2009) have been shown to be hübnerite. Ottens and Cook (2005) however state that wolframite is predominantly ferberite and hübnerite was only found in one single pocket, suggesting that their samples came mainly (all ?) from the skarn-type ore bodies.

ⓘ Hydrobiotite

Formula: K(Mg,Fe2+)6((Si,Al)8O20)(OH)4 · nH2O

✪ Jamesonite

Formula: Pb4FeSb6S14

Habit: Needles to 2 cm

Colour: grey

Fluorescence: none

Description: This material has been sold as Bismuthinite, Boulangerite and Galenobismutite, but it x-rays as jamesonite.

ⓘ Kaňkite

Formula: FeAsO4 · 3.5H2O

ⓘ Kaolinite

Formula: Al2(Si2O5)(OH)4

ⓘ Kobellite

Formula: Pb22Cu4(Bi,Sb)30S69

ⓘ Kutnohorite

Formula: CaMn2+(CO3)2

ⓘ Laumontite

Formula: CaAl2Si4O12 · 4H2O

ⓘ 'Lithian Muscovite'

Formula: KAl2(AlSi3O10)(OH)2

Description: Reported only from the vein-type ore bodies.

ⓘ Malachite

Formula: Cu2(CO3)(OH)2

ⓘ Marcasite

Formula: FeS2

ⓘ Miargyrite

Formula: AgSbS2

ⓘ Molybdenite

Formula: MoS2

References:

ⓘ Muscovite

Formula: KAl2(AlSi3O10)(OH)2

References:

ⓘ Muscovite var. Ferrimuscovite

Formula: K(Al,Fe3+)2(AlSi3O10)(OH)2

ⓘ Muscovite var. Fuchsite

Formula: K(Al,Cr)3Si3O10(OH)2

Description: associated with arsenopyrite and purple apatite

ⓘ Muscovite var. Sericite

Formula: KAl2(AlSi3O10)(OH)2

References:

ⓘ Orthoclase

Formula: K(AlSi3O8)

ⓘ Oxyplumboroméite

Formula: Pb2Sb2O6O

ⓘ Phlogopite

Formula: KMg3(AlSi3O10)(OH)2

ⓘ 'Plagioclase'

Formula: (Na,Ca)[(Si,Al)AlSi2]O8

References:

ⓘ 'Polylithionite-Trilithionite Series'

ⓘ Pyrargyrite

Formula: Ag3SbS3

ⓘ Pyrite

Formula: FeS2

References:

ⓘ Pyrrhotite

Formula: Fe1-xS

References:

ⓘ Quartz

Formula: SiO2

References:

ⓘ Quartz var. Milky Quartz

Formula: SiO2

ⓘ Quartz var. Rock Crystal

Formula: SiO2

ⓘ Ramdohrite

Formula: Pb5.9Fe0.1Mn0.1In0.1Cd0.2Ag2.8Sb10.8S24

ⓘ Rhodochrosite

Formula: MnCO3

ⓘ Scheelite

Formula: Ca(WO4)

References:

ⓘ Semseyite

Formula: Pb9Sb8S21

ⓘ Siderite

Formula: FeCO3

ⓘ Silver

Formula: Ag

ⓘ Sphalerite

Formula: ZnS

References:

✪ Stannite

Formula: Cu2FeSnS4

Habit: Single tetrahedra to 2 cm and complex intergrowth of xls to 6cm

Colour: Brown Black

Fluorescence: none

Description: Rivals South American material for quality.

ⓘ Stephanite

Formula: Ag5SbS4

ⓘ Stibnite

Formula: Sb2S3

ⓘ Stolzite

Formula: Pb(WO4)

Habit: Dipyramidal crystals consisting of combinations of pyramids {101} and {103}; tabular crystals consisting of pyramids {101} truncated by {001}; to 2 mm

Colour: Orange yellow

ⓘ Stromeyerite

Formula: AgCuS

ⓘ 'Tennantite Subgroup'

Formula: Cu6(Cu4C2+2)As4S12S

ⓘ 'Tetrahedrite Subgroup'

Formula: Cu6(Cu4C2+2)Sb4S12S

ⓘ 'Tetrahedrite Subgroup var. Silver-bearing Tetrahedrite'

Formula: (Cu,Ag)6[Cu4(Fe,Zn)2]Sb4S13

ⓘ Topaz

Formula: Al2(SiO4)(F,OH)2

Description: Reported both from the vein and skarn ore bodies.