Ramsdellite

This sample of ramsdellite is displayed in the Smithsonian Museum of Natural History. Ramsdellite is an oxide mineral of manganese with the composition MnO₂ . This sample is about 12x8 cm and is from Lake Valley, New Mexico.

The mass of ramsdellite is a collection of small crystals, like rock chips cemented together.

Mindat: Ramsdellite