Habit: Reddish brown, black or red. Crystals prismatic and elongate on b. Vitreous luster; translucent to nearly opaque. Red streak.
Environment: Occurs in regional metamorphosed rocks of greenschist and amphibolite facies, in metasomatized manganese deposits and in low-temperature hydrothermal veins in altered rhyolites, andesite and diorites.
Etymology: From the locality where it was discovered, Piedmont, Italy, which is Piemonte in Italian.