Pyrolusite

Caland Pit, Steep Rock Lake area, Atikokan, Rainy River District, Ontario  Canada

Specimen size: 2.5 × 2.4 × 2.5 cm = 0.98” × 0.94” × 0.98”
Main crystal size: 0.6 × 0.2 cm = 0.24” × 0.08”