RECENTLY IDENTIFIED EGYPTIAN PIGMENTS

On several bowls from Nubia (1600 b.c. ) and on one canopic jar (New Kingdom) huntite, a calciummagnesium-carbonate CaCO₃. 3MgCO₃ was identified by means of X-ray diffraction and infra-red absorption techniques. Vases from the Amarna period (1370 b.c. ) are decorated with a blue paint, which proved to be cobalt-blue. Copper chloride atacamite was used on limestone reliefs from Thebes-West but the green frit chrysocolla occurs more frequently on Egyptian objects as is mentioned in literature.     

THERMOLUMINESCENCE AND GLAZE STUDIES OF A GROUP OF T'ANG DYNASTY CERAMICS

The application of the recently developed thermoluminescent method of pre-dose dating to thirty-seven glazed ceramics, purporting to have been manufactured during the T'ang Dynasty in China (a.d. 618–906), is reported. The modern origin of eight of these pieces is established. The remaining twenty-nine authentic pieces are discussed with respect to the accuracy of dating possible for such wares. The criterion for authenticity judgement commonly used for this material, that of glaze crackleur, is discussed critically and shown to be of only limited reliability.     

OXYGEN ISOTOPE ANALYSIS AS A MEANS OF DETERMINING SEASON OF OCCUPATION OF PREHISTORIC MIDDEN SITES

By making oxygen isotope palaeotemperature determination of successive growth increments in molluscan food-refuse shells it is possible to determine the sea temperature, and hence the season, at time of death of the shells. Although this is a method which involves the use of sophisticated and expensive equipment, it may under favourable circumstances give extremely reliable results. Shells of the limpet species Patella tabularis in the midden deposits at Nelson Bay Cave, Robberg, Cape Province, South Africa, prove to represent almost ideal material, and are used to demonstrate, contrary to what guesswork might lead one to suppose, that the site was occupied during the winter months.