MnO₂

This sample of manganese oxide is displayed in the Smithsonian Museum of Natural History. Manganese oxide appears as a mineral form of manganese with the composition MnO₂. The sample at left is about 20 cm across and is from Solnhofen, Bayern, Germany. This sample is described as dendritic crystal growth.

Manganese oxide is a synonym for pyrolusite according to Mindat.