Plate 11

Cuprite, the red crystals showing characteristic color, other showing the green tarnish of malachite

Malachite (green) and azurite (blue), the two minerals shown together as they very commonly occur

Plate 12

Limonite

The crystal form in which goethite is found, p is the prism faces, b and c are faces formed by beveling the edges of the prism, o is the pyramidal face characteristic of the ends