A guess, not an answer. You'll see what everyone else said.
Machine-generated description — written by an image model, not by a person.
Vintage scientific crystal X-ray diffraction patterns arranged in a 3x4 grid on a blackboard, labeled with numerical codes (1-31) and German descriptions. Likely from a 1950s–1970s academic or industrial research setting. Useful for mineralogy, materials science, or historical STEM documentation.
