"Aged" autopsy gallstones simulating dry bone context: A morphological, histological and SEM-EDS analysis

The aim of this paper is to provide information on the morphology and composition of gallstones based on clinical samples in order to assist paleopathologists and bioarchaeologists in recognizing their presence in archaeological contexts. 270 gallstones were extracted and macerated from autopsies conducted at the Istituto di Medicina Legale in Milan (Italy) in order to simulate a dry bone recovered from archaeological contexts. Morphological, histological, and elemental variation was documented. Gallstones vary in size, shape, color and texture. The cross-sectional surface correlates with chemical composition and is a valuable tool for classification into subcategories of stones. Histological analysis can confirm the classification. Elemental analysis yielded a higher frequency of carbon, calcium and phosphorus. Although identification of gallstones in archaeological contexts can be challenging, familiarity with morphological, histological, and elemental variation can assist researchers in the field and laboratory. Identifying gallstones in archaeological populations will assist researchers in estimating their frequency in the past and the environmental, cultural, and biological conditions leading to their presence. Small sample size derived from a modern and limited autopsy population may minimize the types and degree of variation present in the past. Effects of climate, soil, and taphonomy were not evaluated. Examination of larger samples derived from diverse populations may reveal greater variation or more diagnostic aspects of stones.