The transformation of high‐resistivity amorphous Bi1.5 SrCaCu2 Ox to superconductive material has been characterized by structural, thermochemical, transport, and magnetic measurements. X‐ray powder diffraction confirmed that rapid solidification of Bi‐Sr‐Ca‐Cu‐O melts yields amorphous materials. Differential scanning calorimetry indicated an exothermic crystallization peak at ∼455 °C with a corresponding enthalpy of ∼50 J/g. Thermal cycling of the insulating glass to a temperature above that required for crystallization results in a transformation from an insulating to a partially superconducting material with an onset temperature of 85 K.