This limestone matrix is covered by a matted, felted mass of acicular, lustrous, gray, boulangerite: a lead, antimony, sulfosalt, in crystals, to 1.75 cm across. Cubes of mirror-bright pyrite, to .5 cm across, also dot the matrix. This is an excellent example of the acicular crystal habit of boulangerite, well known historically from Zacatecas.