Chalcophanite is a rare copper manganese oxide mineral that typically forms in the oxidation zones of copper and manganese deposits.

Chalcophanite typically appears as fine-grained, dark-colored masses, often in earthy or botryoidal (grape-like) formations. Its surface can be smooth, and it may also display a slight iridescent sheen depending on the specific conditions of formation.

While chalcophanite is not a commercially important mineral, it has scientific value. It is studied in mineralogy for its unique composition and formation process, particularly because of its relationship with the alteration of copper and manganese ores. Its striking color and rarity make it of interest to collectors of rare minerals.