A laboratory experiment is described in which a simple characterization of a historical lime mortar is made by the determination of its approximate composition by a gravimetric method. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) are also used for the qualitative characterization of the lime mortar components. These types of experiments are particularly suitable to teach aspects of general chemistry and to present techniques such as FTIR or XRD at an introductory laboratory level to students who have their major in courses that are related to cultural heritage but also have science disciplines, such as chemistry.