Krohnkite itself is a bizarre species, occurring in good crystals of size only at this classic, sadly under-appreciated locality. Specimens today are rare, in crystal form, although massive pieces are much more common. This piece is a strange krohnkite specimen with unique green-blue crystals in the center of this cluster, which I thought might be Lindgrenite at first. However, they are just krohnkite with some kind of unusual composition, as the crystal habit is right and the green hue grades into blue.