F ig . 6. Se-bearing galena (11.4–11.8 Se wt%) on the surface of wittite. The spots indicate different Se contents in wittite:1) 8.65 wt%, 2) 8.45%, 3) 9.62%, 4) 9.99 %.

F ig . 9. a) The first type of SAED pattern for wittite from Vulcano with strong H subcell reflections. b) The second type of SAED pattern for wittite from Vulcano with strong H and Q subcell reflections. c) The third type of SAED pattern with strong H and Q subcell reflections and another

F ig . 9. a) The first type of SAED pattern for wittite from Vulcano with strong H subcell reflections. b) The second type of SAED pattern for wittite from Vulcano with strong H and Q subcell reflections. c) The third type of SAED pattern with strong H and Q subcell reflections and another

F ig . 9. a) The first type of SAED pattern for wittite from Vulcano with strong H subcell reflections. b) The second type of SAED pattern for wittite from Vulcano with strong H and Q subcell reflections. c) The third type of SAED pattern with strong H and Q subcell reflections and another

TABLE 3. UNIT SUBCELL VALUES OF WITTITE AND CANNIZZARITE

TABLE 1. ELECTRON-MICROPROBE DATA ON WITTITE AND CANNIZZARITE FROM VULCANO

TABLE 2. X-RAY POWDER-DIFFRACTION DATA FOR WITTITE AND CANNIZZARITE

F ig . 1. Location of fumaroles at La Fossa crater from which cannizzarite and wittite were sampled.

F ig . 10. Volumes (Å 3 ) of the H and Q subcells increase with increase in Se content in cannizzarite and wittite.

F ig . 8. Relation between Se/(S + Se) and Bi/(Bi + Pb), both in at.% in 141 analyzed samples of cannizzarite–wittite.

F ig . 4. Striated elongate crystals of wittite (Se ≈ 10 wt%) with small crystals of galena on the surface. CamScan 4DV scanning electron microscope. Scale bar: 100 μm.

F ig . 3. Morphology of wittite crystals (Se content ranging from ~8 to ~14 wt %. Variation of color is due to the Se contents; the highest Se contents are in the darkest portions. a) Leaves, scale bar: 100 μm, b) elongate tabular crystals, scale bar: 300 μm.

: krupkaite, Lds: lindströmite, Lil: lillianite, Lrs: larosite, Mat: matildite, Mky: makovickyite, Mum: mummeite, Ney: neyite, Nuf: nuffieldite, Our: ourayite, Paa: paarite, Pad: paděraite, Pav: pavonite, Slz: salzburgite, Spb: schapbachite, Trs: treasurite, Vik: vikingite, Witc: wittichenite, Witt: wittite

(+) Mawsonite (+) Stannoidite (+) Carrollite (+) Covellite (+) Pyrrhotite (+) (+) (+) (+) (+) (+) (+) (+) (+) Bismuth (+) (+) Gustavite (+) Junoite (?) (+) Wittite (?) (+) Cannizzarite

F ig . 11. Back-scattered electron images. (a) and (b) Inclusions of Te-bearing laitakarite (Ltk) within pyrrhotite (Po) in gold ores, Lega Dembi mine, Ethiopia. Hs: hessite, Bi: native bismuth. (c) Deformed lamellar intergrowths of laitakarite (Ltk) and wittite (Wit) from the Falun deposit