Tennantite subgroup

The reclassification and revised nomenclature rules for minerals of the tetrahedrite group (Biagioni et al. 2020a) have led to the approval of several newly defined species as members of a tennantite subgroup; these new minerals would previously have fallen under the single species name "tennantite". A general formula for the tennantite series can be written as Cu₆(Cu₄M₂)As₄S₁₃ with each species defined by M, which can be Cd, Cu, Fe, Hg, Mn, Ni or Zn.

Further work is needed to be confident which of these newly defined species are present at Tsumeb and in what proportions but it appears from published analyses and recent investigations that the hypogene tennantite is predominantly tennantite-(Zn), while quantitative WDS analysis has indicated the relatively rare occurrence of tennantite-(Cu) as a pseudomorphous replacement after enargite (M. Števko and M. Southwood; unpublished data).

Tennantite-(Fe) has been reported as a matrix component in a specimen in the collection of Walter Veldsman on which Joy Désor identified berthierine in association with ludlockite and leiteite (https://www.mindat.org/photo-1169313.html; accessed December 2023). However, tennantite-(Fe) has not been included in the Mindat list of minerals for Tsumeb; neither has analytical data been provided. Its status at Tsumeb is considered questionable pending verification.

Please refer to the notes on tennantite-(Cu), tennantite-(Fe)  and tennantite-(Zn) for further information on the occurrence of tennantite subgroup minerals at Tsumeb.

adamite; andyrobertsite; anglesite; argutite; argyrodite (?); arsendescloizite; arsentsumebite; arthurite (?); austinite; azurite; bartelkeite; baryte; bayldonite; beaverite-(Cu); bendadaite; berthierine; betekhtinite; bornite; briartite; brochantite; brunogeierite; calcioandyrobertsite; calvertite; cerussite; chalcocite; chalcopyrite; clausthalite; conichalcite; cupropearceite; cupropolybasite; devilline; dolomite; duftite; enargite; erikapohlite; euchroite (?); eyselite; fahleite; ferrilotharmeyerite; fleischerite; freedite (?); galena; gallite; gallobeudantite; germanite; germanocolusite; gypsum; helmutwinklerite; hörnesite; jamesonite (?); jarosite (?);  johillerite; karibibite; kësterite; keyite; koritnigite; köttigite; krieselite; lammerite; langite; larsenite; lavendulan; leiteite; lepidocrocite (?); linarite; ludlockite; malachite; mawsonite; mimetite; molybdenite; mottramite; o’danielite; ojuelaite; olivenite; otjisumeite; ovamboite; parnauite (?); posnjakite; powellite; pyrite; quartz; queitite; renierite; rutile; schaurteite; schneiderhöhnite; schultenite; scorodite; serpierite; skorpionite (?); smithsonite; söhngeite; spertiniite; sphalerite; stannite; stibioclaudetite; stolzite; stottite; stranskiite; stromeyerite; tsumcorite; tsumgallite; velikite (?); warikahnite; wroewolfeite (?); wulfenite; wurtzite; yvonite (?); zincolivenite; zincroselite