This is a Brazilian classic from the "old era" of the Golden Days of mineral collecting in Brazil (1950s-1960s), as related to me by the elders like Pinch, Bancroft & Swoboda. They treasured specimens from the Morro Velho Mine for its interesting mineralogy and aesthetic combinations, more than any few gold specimens. This piece has elegant quartz crystals as the pedestal for glistening, superb, amber-colored siderite. The siderite from this mine was long considered best of species by most folks (except French or English collectors who think their countries produce the best). Beyond the obvious aesthetics here, we can also look closer and see platy crystals of pyrrhotite to 1 cm or so, and sharp, small crystals of cubanite, to 2 or 3 mm, decorating the specimen and adding iridescent golden color and sparkle. We only see these turn up in old collections now.