A galvinol derivative bearing the 3,5-dipheny1-4-hydroxyphenyl substituent exists in three polymorphic forms, i.e., I (melting point, 208 degrees C), II (203 degrees C), and III (138 degrees C), which are interrelated as monotropic polymorphs. Of these forms, III exhibits multiple melting behavior. The relative thermodynamic stability of the three forms was determined and is represented in a semischematic energy/temperature diagram. All three forms, once melted and cooled, solidify to form glass with a glass-transition temperature of 109 degrees C.