Approximately one hundred framboids from coals, shales and lake bottom sediments have been individually examined by x‐ray diffraction (XRD) to determine their composition and their structure. Fresh, lake bottom framboids were largely composed of greigite accompanied with kaolinite. Aged, lake bottom framboids were mixtures of greigite and pyrite. Coal and shale framboids are predominately composed of iron pyrite either entirely or accompanied with other compounds. Occasionally, framboids were found entirely encased by quartz. Some framboids were composed of materials that could not be identified. The pattern of one such framboid was indexed with a tetragonal cell having the dimensions a = 4.1288 A˚ and c = 8.2400 A˚. The Laue XRD patterns indicated that the microcrystallites of framboids were randomly oriented; no preferential orientation was found. It is concluded from these patterns which exhibit spots plus a continuous halo that the cementing material is a fine grain version of the same material of which the framboid is composed.