A truly remarkable specimen with rich coverage of twinned cubanites, including that wonderful, 1.2 cm cyclic twin sitting front and center, all on crystallized and contrasting calcite matrix! Large cubanite specimens are godawfully rare and the pieces from this mine set the standard. However, good specimens are usually just miniatures or thumbnails - to get crystals of such quality, and so richly, on matrix, is almost unheard of today. Large pieces are even more uncommon. This is a superior specimen, worthy of a museum.