Santa Eulalia District, Mun. de Aquiles Serdan, Chihuahua, Mexico
Small Cabinet, 8.8 x 8.2 x 4.4 cm
Goethite takes on such a huge variety of forms - often really strange, as here, where it has pseudomorphed underlying crystals of selenite. The form of the selenite blades, which are no longer extant (you can clearly see their hollow imprints underneath) have been perfectly preserved by the dark goethite, which would have been totally amorphous but for its deposition on these euhedral crystals. Ex. Jaime Bird Collection.