This unususal specimen has always been one that caught my eye in Jack's collection. It is simply unique in my experience. The piece has, superficially, the yellow color one would normally associate with Moroccan anglesite of modern days. However, the matrix (sulfide-rich) and the copper mineralization atop (probably posnjackite and/or langite) simply scream "Tsumeb!." Rare, unusual, and pretty....as so many of Jack's pieces are.