These specimens of manganite partially replaced pyrolusite, come from a locality not yet described in the mineralogical bibliography. This deposit is located in the province of Boulemane, in the Fez-Meknés region, about ten kilometers from the well-known Aouli mines. It is a formation very similar to that of Imini (near Ouarzazate). These manganese deposits, both in Imini and in the Boulemane area, were formed in a karst system. Associated with shallow marine dolomites of the Cretaceous age and that currently form sub-horizontal mantles cutted by erosion, overlaping areas of volcanic rocks. Manganese minerals are found in dolomite breccia and ferruginous clays. We have carried out X-ray diffraction studies showing us the presence of both species: manganite and pyrolusite.