GREEN THESSALIAN STONE: THE BYZANTINE QUARRIES AND THE USE OF A UNIQUE ARCHITECTURAL MATERIAL FROM THE LARISA AREA,GREECE. PETROGRAPHIC AND GEOCHEMICAL CHARACTERIZATION

The quarries of ‘green Thessalian stone’ provide important information about the use of materials and the application of technology in late antiquity. This stone was used for decorative purposes in Imperial Rome and especially in Byzantium. Sarcophagi, column shafts, facing slabs, tubs, ambones, iconostaseis and baptismal fonts are still found in places stretching from Syria to Britain and from Tunisia to Germany, as well as Rome, Constantinople and Thessaloniki. There are two important areas of quarrying at the Chasanbali Hill in the Larisa area of central Greece. At the southern site, quarrying operations took place mainly in late Roman times, whereas the northern quarrying zone provided mostly raw materials for making pillars and other architectural pieces during the Byzantine period. Green Thessalian stone is composed of an ophicalcite, a mosaic of green serpentinite and white marble fragments. Mineralogically, the Larisa ophicalcite consists largely of serpentine, calcite, magnetite, haematite and chromite. Chemical analyses reveal a high quantity of CaO (26.39 to 31.00 wt%), while Cr varies between 940 and 1430 ppm. C and O isotopic compositions of the marble inclusions show δ¹³C values ranging from +3.12 to +3.31 ‰ and δ¹⁸O values from ?12.98 to ?13.11 ‰.