Abstract Ravenna represented an important administrative, commercial and cultural centre in the fifth and sixth centuries. The present study explored the commercial mechanisms of Ravenna in Late Antiquity from the point of view of the marble trade, as well as the trade in other architectural elements. A portion of the research is based on the macroscopic and quantitative study of stone materials (around 1000 fragments) from the Late Antique and medieval complex of San Severo in Classe (Ravenna, Italy). The results indicated that the predominant commercial relationships of Ravenna with respect to stone artefacts (marbles, limestones, porphyry, breccia, granites) were orientated mainly towards the regions of Asia Minor, with some trade also occurring in minor quantities with North Africa, Greece, Italy, and France. Three representative marble samples were analysed to make determinations of their provenance. The methods used were based upon a combination of petrographic image analysis, polarizing and cathodoluminescence microscopy of thin sections, and stable isotope geochemistry of carbonates. The Proconnesos and, eventually, other Turkish provenance of the selected samples is considered.

Abstract This paper represents the introduction to the volume focused on the various aspects of natural stone research. From the topic issues studied recently, four major aspects are covered: (1) availability of certain stone types for monuments, (2) strategies aiming to strengthen our knowledge of past resources through the establishment of natural stone databases and inventories, (3) evaluation of natural stone properties and assessment of the compatibility of repair stones, and (4) decay studies of natural stone on monuments and on natural exposures. This paper also aims to highlight the importance of the use of local stone resources, a practice that has seriously declined during the 20th century in most of the industrialized countries. The availability of natural stone from monuments is also discussed in terms of sandstones and travertine in the Czech Republic and Hungary as a typical example.

Abstract This study reports the Raman data for reduced carbonaceous matter (CM) in crystalline marbles, related to a determination of their provenance. Raman microspectrometry was tested on ‘graphitic’ marbles formed under different metamorphic conditions (regional v. contact) with various geological ages, and with distinct types of CM from the Bohemian Massif (Czech Republic). First, various modes of occurrence of CM were examined by optical microscopy (OM). The Raman results exhibited spectral variations of CM with different metamorphic grades and types. Several marble groups could be distinguished: (1) well-ordered CM/graphite of higher grade regional metamorphosed marbles; less graphitized metamorphosed organic matter (‘disordered’ CM); (2) low-grade regional metamorphosed rocks, and (3) contact metamorphosed marbles.

Abstract The structure of the electronic database of natural stones used in the Czech Republic (named Deka ) has been completed. The system is based on MySQL, and is comprised of the following crucial items: general data, data regarding the geographic location and status of the quarry; petrographic description, associated mineralogical data and chemical analyses; technical data covering physical and mechanical properties as well as sculptural workability; parameters about the deposit (quarry); and data describing historical exploitation and utilization. Along with the structure of the database, other practical problems such as access to the database, insertions, corrections, erasing a record or reference, etc. are discussed. The database is designed for geologists, historians and restorers resolving problems of a stone's provenance from monuments, architects involved in the selection of promising stone types for new projects and for educational purposes to geologists, restorers, etc. Appendix 1: A description of the eight types of data used in the dimension store database is provided at http://www.geolsoc.org.uk/sup18394