Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
Van Tassel (1966) originally described "his" material as being "a strunzite-like material, completely Mn-free and with little or no divalent FeO". However, due to a lack of sufficient data, it was not submitted as a possible new species at the time.
Later, Peacor et al. (1987) state that the mineral they name "ferristrunzite" is "essentially the Fe3+ analogue of strunzite and ferrostrunzite", i.e. exactly the same "Mn-free strunzite" as reported by Van Tassel back in 1966.
In 1990, when Dillen & Van Goethem described ferristrunzite from Haut-le-Wastia (Dillen, H., Van Goethem, L. (1990) Ferristrunzite. Bulletin van de Belgische Vereniging voor Geologie, 99(3-4), 399), Van Tassel confirmed again that any and all "strunzite" from Blaton he had analysed over the years, had turned out to be recently named ferristrunzite (Rik Dillen, pers. comm.)
