Frank Keutsch's Photo Gallery

74R-V7UZincobriartite Cu₂(Zn,Fe)(Ge,Ga)S₄

Kipushi Mine, Kipushi, Kipushi Territory, Haut-Katanga, DR Congo

Dimensions: 41 mm x 30 mm x 15 mm

Nearly pure mass of zincobriartite. EDS analyzed. Purchased from Mark Wrigley Thames Valley Minerals.

TC1-325Cupropearceite [Cu₆As₂S₇][Ag₉CuS₄] , Cupropolybasite [Cu₆Sb₂S₇][Ag₉CuS₄]

Tsumeb Mine, Tsumeb, Oshikoto Region, Namibia

Largest Crystal Size: 0.3 mm

Extremely copper-rich cupropearceite xx with small zones (bright) of cupropolybasite.

E9G-0C9Nickeline NiAs , Breithauptite NiSb

Balcoll Mine, Falset, Priorat, Tarragona, Catalonia, Spain

Largest Crystal Size: 0.15 mm

EDS analyzed.

Crystals consisting of a core of pure breithauptite with overgrowth of low-Sb nickeline. In my opinion, the visible part of the crystals consist of nickeling unless they are broken.

49G-2PCBillingsleyite Ag₇AsS₆ , Alabandite MnS

Uchucchacua Mine, Oyón District, Oyón Province, Lima, Peru

Billingsleyite crystal aggregate on alabandite. The crystal was removed for single crystal XRD (P213, a=10.46) and afterwards mounted in a polished section for EDS analysis (Ag7AsS6, no Sb). Twinning was observed in XRD.

2RH-D7YRhodostannite Cu¹⁺(Fe²⁺_0.5Sn⁴⁺_1.5)S₄ , Andorite AgPbSb₃S₆ , Woodhouseite CaAl₃(PO₄)(SO₄)(OH)₆

San José Mine, Oruro, Cercado Province, Oruro, Bolivia

Pseudo-octahedral rhodostannite xx scattered on andorite together with probable woodhouseite. Picture width 2cm. Andorite and rhodostannite SEM/EDS and XRD confirmed. EDS indicates woodhouseite.

PRV-UT1Löllingite FeAs₂

Samson Mine, St Andreasberg, Braunlage, Goslar District, Lower Saxony, Germany

Lollingite crystal aggregate XRD and SEM/EDS confirmed.

92R-J75Arsenopyrite FeAsS

Samson Mine, St Andreasberg, Braunlage, Goslar District, Lower Saxony, Germany

Arsenopyrite crystal aggregate XRD and SEM/EDS confirmed.

C56-C0ELöllingite FeAs₂

Ightem Mine, Ightem, Tansifte Caïdat, Agdz Cercle, Zagora Province, Drâa-Tafilalet Region, Morocco

Lollingite crystals to 8 mm. The specimen was received as rammelsbergite and like all other crystallized rammelsbergite I have analyzed (XRD/SEM-EDS) from the Bou Azzer region turned out to be lollingite.

Mindat.org Photo of the Day - 18th Dec 2019

FLF-4XEKostovite CuAuTe₄ , Gold Au , Weissite Cu_2-xTe

Kalgoorlie-Boulder Shire, Western Australia, Australia

The black vein consists of nearly pure kostovite with gold and abundant but microscopic weissite. In polished section melonite and nagyagite can also be identified. Specimen size ca. 2 cm wide.

VUP-5R7Milotaite PdSbSe , Gold Au , Chalcopyrite CuFeS₂ , Hakite-(Hg) Cu₆(Cu₄Hg₂)Sb₄Se₁₂Se , Tetrahedrite Subgroup Cu₆(Cu₄C²⁺₂)Sb₄S₁₂S , Clausthalite PbSe

Předbořice deposit, Předbořice, Kovářov, Písek District, South Bohemian Region, Czech Republic

Bright slightly beige appearing milotaite (M) together with cuprian gold (Au), chalcopyrite (Ch), clausthalite (C), sulfur bearing, Hg-free hakite (H) and selenian tetrahedrite (T). The milotaite in this specimen typically contains contains a little Bi. The assemblage is distinct from the original description. The gold grain in the center is about 15x35 micron.
The specimen, possibly only the second known milotaite, also contains tiemannite, eucairite, uraninite, umangite, bukovite, naumannite, ferroselite, klockmannite and merenskyite.