As part of master's thesis, the provenance of querns from Emona, which are kept in the City Museum of Ljubljana, was investigated based on petrographic-mineralogical and geochemical analyses. Querns are small stone hand mills that were widely used during the Roman period. The Romans mostly made querns from local rocks and exported them within a limited geographical area, no further than one hundred kilometres. Eleven samples of Roman querns from Emona were examined macroscopically, and thin sections were prepared for optical microscopy. The mineral composition was determined using X-ray powder diffraction (XRD), while the elemental composition was determined by inductively coupled plasma mass spectrometry (ICP-MS), which provided content of major oxides. The results were statistically treated using PCA factor analysis. Based on the analyses, samples were divided into three main groups: clastic rocks (quartz sandstones: samples DM1, DM3, DM8, DM9 and DM11; lithic sandstones: samples DM4, DM5 and DM7; feldspar sandstones: sample DM2), carbonates (limestone: sample DM10) and volcanoclastic rocks (litoclastic tuff: sample DM6). The provenance was determined based on the type of rock and its petrographic-mineralogical characteristics, and finally through a comparative analysis of chemical composition data with reference values from already known sites. The geochemical data of the Emona samples were first compared with known data from local quarries (up to 10 km away), then with regional sources (up to 40 km), and finally with sources more than 40 km away. The sample of quartz sandstone (DM1) could originate from the Roman quarries in the area of Ljubljana Castle, or it may belong to the Koprivnik Member of the Gröden Formation. The potential source area for the lithic sandstones (DM4 and DM7) includes the Pseudozilian beds in the Cerkno and Škofja Loka hills, or the Amphiclina beds in Cerkno (sample DM4). The limestone sample (DM10) could originate from Podpeč. For the remaining samples, the provenance could not be determined.
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