Goethite pseudomorph after Marcasite

Reference: 1390

Goethite pseudomorphs after pyrite are relatively common but in a small area of south Swaledale unusual pseudomorphs of gothite after marcasite occur. This specimen from Whitaside mine shows sharp striated  'marcasite' crystals completely replaced by goethite. Whilst they are not associated with any other minerals, epimorphs on the underside suggest they originally formed over spheres of coxcomb barite.

Formulas: Goethite Fe³⁺O(OH) ; Marcasite FeS₂

Status: Sold

Dimensions: 72x60x15mm

Size: Small Cabinet (S)