SEM-EDX micro-analysis and FTIR infrared microscopy by ATR of a bladder stone from the IIIth millennium BC from the B1S passage-grave of the necropolis in Chenon (Charente, France)

Abstract

Here is a case of bladder stone of average size dated to the Late Neolithic period, found in the multiple burial of the B1S passage-grave in Chenon (Charente, France). Chemical analysis showed a mixed composition. The core, intermediate and surface envelopes consist in calcium phosphate apatite associated with whitlockite and amorphous carbonated calcium phosphate, all clarified by Fourier Transform InfraRed spectroscopy. Calcium phosphatic stones are characteristic of communities, such as those of the Neolithic period, where the diet was rich in cereal carbohydrates and poor in animal proteins. The excavation of such extra-skeletal objects is an event that is particularly interesting as it provides documents on the history of diseases and diets in ancient populations. The complete set of data suggests that this bladder stone was formed during a urinary tract infection with a germ possessing a very active urease.

Keywords

• Infectious stone
• Carbapatite
• Whitlockite
• Amorphous carbonated calcium phosphate
• FTIR spectroscopy
• Microchemical analysis
• Urease