The highlight of this specimen is the series of parallel growth, disc-shaped galena crystals, to 6 cm across. They are replacements (pseudomorphs) of pyrrhotite, by galena. Each of the larger galena crystals is backed by sugary, white calcite making an interesting color contrast between the two species. All of this is emplaced on a matrix of smaller galenas of normal habit, atop light green fluorite. Although not in the Heck collection of Mexican minerals, this piece fit well with the update and is included. It was long in the collection of noted California collector Ed Swoboda, who specialized in pseudomorphs. When his collection sold to Carter Rich in the mid 1990s, the piece went next to Dr. Ed David. I got it from Ed in a deal in about 2002, and sold it to Mexico & Arizona-collecting specialist David Stoudt, from whom I obtained it back by exchange recently.