Grey and Greyish Banded Marbles from the Estremoz Anticline in Lusitania

This contribution addresses the characterization study of grey and greyish banded marbles from the Estremoz Anticline (EA) marble district in Portugal. During Roman times, the whole of Lusitania, including its capital Augusta Emerita, was supplied with white and coloured marbles from this district. Grey varieties were used mainly in architectural and epigraphic elements, funerary stelae and arae. The interest in the EA marbles focuses here on the grey types as they could have been used for trading beyond their provincial administrative domains, as was the case with the white marbles, in competition with other Iberian and classical materials, creating an increasing need to know how to identify them. A multi-method approach combining visual examination, spectrophotometry to quantify the greyscale tones, optical microscopy (OM), cathodoluminescence (CL) and stable C and O isotope analysis was applied to 25 quarry samples, which were collected from the south-eastern part of the EA structure.