Acanthite Ps. After Argentite on Calcite
Valencia Mine, Guanajuato, Guanajuato Prov., Mexico
Small Cabinet, 6.2 x 5.4 x 5.3 cm
Neatly perched on a matrix of white, botryoidal calcite is a cluster of dark gray, matte luster, crystals of acanthite after argentite. The largest cube measures .45 cm across. The label on the back side of this specimen indicates that it was mined in 1892. It later entered the collection of the University of Chicago, in 1964. It is a super locality piece because acanthites on such matrix are rare, but the dated label is surely a bonus and gives solid locality designation as well!