The Gandolfi camera, which produces simulated powder diffraction patterns from single crystals, has been found to be a very useful tool in applied mineralogical research. For many micro-diffraction problems, the advantages of the method far outweigh its weaknesses, and Gandolfi films are usually quite adequate for identification purposes. A simple modification to the small Gandolfi camera permits the recording of low-angle reflections corresponding to d-spacings of nearly 14 angstroms for CuKα radiation. Applications of the method include identification of radioactive minerals, other heavy minerals, contaminants, and glass stones.