GOETHITE PSEUDOMORPHS: THE PRESENCE OF PYRITE CRYSTALS WITHIN GOETHITE AFTER PYRITE PSEUDOMORPHS FROM THE PIEDMONT PROVINCE OF WESTERN GEORGIA

Goethite pseudomorphs after pyrite have been collected from the Piedmont physiographic province of West Georgia, near the Carroll County area, and show a complex history of formation. The rock the pseudomorphs occur in is a muscovite schist containing quartzite; some of the rock displays red/brown iron oxide staining in narrow bands around the pseudomorphs. The pseudomorphs externally appear to be that of a simple cube, maintaining sharp, orthogonal angles. Internally, the pseudomorphs contain a wiry, box-work pattern, in which examples of unaltered pyrite occur. The pyrite is not in its original crystal form, but maintains the same luster and color as fresh pyrite. Native sulfur crystals have also been found, along with an assortment of silica and mica minerals. Along the edges of the pseudomorphs, a clear border of uniform goethite exists in all the samples. However, voids also exist within the goethite matrix, most being orthogonal. Pyrite is believed to have been originally filling in these samples. In some samples, goethite has surrounded the pyrite, forming a zone of noticeable discoloration. In other samples, the pyrite occurs in the open boxes with little contact with the goethite. Chemical traces are being determined to quantitatively show the weathering and oxidation of the pyrite into goethite, leaving large percentages of sulfur, and notable traces of aluminum. Scanning electron microscope analysis is being used to elementally map the goethite after pyrite pseudomorphs, collecting elemental percentages in the goethite, pyrite, and zone of discoloration.