Goodchild, of the Scottish Geological Survey, found wulfenite there in 1875 but the locality only really became of interest to collectors in the 1950s following the reporting of a suite of rare supergene minerals including bayldonite, duftite, beudantite, carminite, lindgrenite and stolzite
(the first authenticated British occurrence).
Greg and Lettsom (1858) cite the Force Crag mine as the first occurrence of stolzite
ever found in England, though later writers believe that stolzite
is unlikely there, given the mineralogical and geological setting of the vein.
There are also, of course, much fancier items in the collection, including sharp floater crystals and twins of some truly rare species: senarmontite, glaucodot, stolzite
, hambergite, neptunite, epididymite, a petite cumengite "mace" on boleite, and (naturally) a superb specimen of a member of the whiteite group, specifically of whiteite-(CaFeMg).
and Embolite, Broken Hill, New South Wales, Australia, no.
Cerussites, fine rhodonite in galena and especially a world-class stolzite
garnered the most praise.
The world's best stolzite
crystals, we now know, are orange 3-cm bypyramids (which look just like wulfenite) from a 1993 Tsumeb pocket.
Associated minor minerals occurring as coatings in fractures, include tourmaline, topaz, apatite, titanite, rutile, stolzite
, arsenopyrite, bornite, chalcopyrite and molybdenite (in no particular order).