The combination of spectroscopy and microscopy enables unprecedented insights into the molecular and crystal structures of organic and inorganic materials, and their interfaces. This is relevant to the field of biomaterials in general and biominerals in particular. In this framework, we extensively analyzed various proteins, minerals and biominerals. Here we present two novel observations: x‐ray absorption near‐edge structure (XANES) spectroscopy at the carbon K‐edge is sensitive to protein misfolding and aggregation into amyloid fibrils, and to the polar and azimuthal rotation of the CaCO3 polymorph aragonite.