MINERALOGICAL AND PETROLOGICAL INVESTIGATION OF HISTORIC ST. MARY'S CITY, MARYLAND ORANGE MICAEOUS CERAMICS

Seventeenth century utilitarian orange micaeous ceramics from the site of Historic St. Mary’s City, Maryland were investigated using optical mineralogical techniques and archaeological attribute analysis. Two groups of sherds were separated by decoration and typology. No glazes were found, although a slip may have been applied. The paste has been fired to greater than 550ºC and reflects complete oxidation. The aplastic components (temper) were identified as minerals (quartz, muscovite, biotite and feldspar), rock fragments and grog. The abundance of the individual temper components varied among the sherds, however the components were all represented. Quartz is found as subangular to subrounded monocrystalline mineral grains and polycrystalline rock fragments. Some of the monocrystalline quartz contained rutile needle inclusions. Muscovite is much more abundant than biotite and feldspar. Grog is rounded, reddish black to black and represents refired ceramic material. Although these sherds have been tentatively assigned as Spanish Merida in origin, these results suggest that these wares could have been manufactured at or near the site of Historic St. Mary’s City.