My periodic table poster is now available! Manganite. Description from the source: Manganite (Mn+3O(OH) mon.), Ilfeld, Harz, Germany. Very good crystals in matrix. 4x3,5x2,5 cm; 15 g. Source: Simone Citon Contributor: John Gray Acquired: 26 September, 2008 Text Updated: 28 September, 2008 Price: Trade Size: 1.6" Composition: Mn.3O(OH)