Group of very sharp pyrolusite tabular crystals showing polysynthetic growths, unusual for the species. Good luster, metallic gray color. The echeloned faces gives them a different aesthetics. In the matrix we can observe more classic acicular radiated pyrolusite crystals.
Few specimens were obtained and, at first, it was thought that by their shapes and color tones they were marcasite, but further analysis characterized them as pyrolusite. Probably the best pyrolusite Spanish specimens.