Here's remarkable fossil pseudomorph of goethite after marcasite. Originally mined by French dealer Alain Carion and his son in the remote western desert of southwest Egypt, these pseudomorphs underwent a fascinating transformation from marcasite to iron hydroxides, primarily goethite.
These goethite pseudomorphs stand out for their aesthetic appeal and offer a glimpse into the dynamic world of fossils and mineralogy, making them a welcome addition to any mineral collection.