Canadian Mineralogist Yol. 29, pp. 4l l4l8 (1991) JOLLIFFEITE AND UNNAMED GOASSE: TWO NEW ARSENOSELENIDES FROM THE

• Main Authors: North Shore, Of Lake Athabasca, Louis J. Cabri, J. H, Gilles Laflamme, Andrew C. Roberts, Alan J. Criddle, Larry J. Hulbert
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: new mineral species; jolliffeite; NiAsSe; unnamed CoAsSe; gold (Ag; Pd; Cu; Hg; X-ray-dif- fraction data; electron-microprobe data; reflectance; Bayliss; Fish Hook Bay; Lake Athabasca
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.589.8502; http://rruff.info/doclib/cm/vol29/CM29_411.pdf

Jolliffeite (ideally NiAsSe) and an unnamed mineral [(Co,Ni)AsSe], referred to as "unnamed CoAsSe", are new minerals found in samples from the Shirley Peninsula (Fish Hook Bay area), Lake Athabasca, Saskatchewan. The two new arsenoselenides occur as small discrete anhedral grains, closely associated with clausthalite and unidentified Bi and Pb-Bi-Ag selenides in a pitchblende-rich fracture zone. Jolliffeite is white in plane-polarized reflected light, nearly isotropic, and the reflectance spectrum is flat (e.g., Rr 50.190 at 400 nm to 51.20/0 at 700 nm, in air). It is chemically and crystallographically tJre Se-analogue of gersdorffite-Pa3, with an a of 5.83 I (l) A, and belongs to the pyrite subgroup of Bayliss (1986); D(calc) = 7.10 g/cm3 for Z = 4. The unnamed CoAsSe has similar optical properties to jolliffeite, except that it is slightly more anisotropic. The powder pattgrn could not be indexed; the three strongest lines [d in A (4] are: 2.592(LM),2.365 (80), 1.746(60); the pattern differs from that of synthetic CoAsSe, quenched from 800'C and from 300"C. Neither pattern can be indexed on the orthorhom-bic cell of Nahigian et al. (1974). Jolliffeite honors the late A.W. "Fred " Jolliffe, for his contributions to the commercial exploration of this area of northern Sas-katchewan.