“Villiaumite is a rare mineral in the Saint-Amable sill. Mostly it occurs as cavity fillings, anhedral grains, or, at best, crude, etched/leached, crystals with an occasional face here and there. This is the best crystal that I have ever seen from here. It isn't perfect, but it is in pretty good shape and is even lustrous. (The dark zig-zag on the most lustrous face is actually a reflection even though it looks like a shadow in the photo). I don't think that any of the faces are cleavages.
According to the Min Rec special issue on this quarry (March/April 1998), villiaumite was first found here ca 1994. This specimen was found in November 1999, but I only noticed this particular crystal recently. As in the 1994-6 find, assocaited minerals include serandite, eudialyte, zakharovite, aegirine and natrolite, but there is no varennesite, makatite, or vuonnemite. Instead, there is (locally) abundant nenadkevichite, yofortierite and/or tuperssuatsiaite (none of these on this specimen) and a couple of unidentified mineras (including the yellowish stuff shown in the photo) currently awaiting EDS. For Demix-Varennes, this was a very rich find of villiaumite.
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Modris Baum - 17th December 2017