This is old Santa Eulalia smithsonite - not Choix! As such, it is incredibly large and rich, very hard to find specimens such as this around for the locality. It is olive-colored, with a pearly, almost iridescent luster. The only contact is on the bottom; the smithsonite is piled up centimeters thick, culminating in knobby botryoidal forms. Ex. Dave Stoudt collection.