What is "jolliffeite"

n. (context mineralogy English) An isometric-diploidal tin white mineral containing arsenic, cobalt, nickel, and selenium.

Jolliffeite is a rare selenide mineral with formula NiAsSe or (Ni,Co)AsSe. It is the selenium analogue of the sulfide mineral gersdorffite, NiAsS, with a common impurity of cobalt, CoAsSe. It is named for its discoverer, Alfred Jolliffe, (1907–1988), a Canadian geologist of Queen's University, Kingston, Ontario.