Description
Rare specimen of Goethite. A pseudomorph of pyrite
In mineralogy, a pseudomorph is a mineral that appears in an atypical form resulting from a substitution process in which the appearance remain constant, but the original mineral is replaced by another. The name means “false form”.
Goethite is a mineral of the diaspore group. It is found in soil and other low-temperature environments such as sediment. Goethite has been well known since ancient times for its use as a pigment.