Manganosite is a rare manganese oxide and usually is found as irregular grains or masses. This very rich, old-time specimen from Langban, Sweden features rare octahedrons, subhedral crystals and massive manganosite. The fresh, broken emerald-green crystals darken to brown or black upon exposure. This is a very rich, very uncommon example of the rare species and world-famous locale. Ex. Dennis Mullane Collection and accompanied by an older, faded Burminco label from the 1950s or 1960s.