High-resolution calorimetry on thermal behavior of glycerol (I): Glass transition, crystallization and melting, and discovery of a solid-solid transition

► Observation of crystallization of glycerol on warming at rates from 50 μK/s to 4 mK/s. ► Glass transition temperature depends on scanning rate with Arrhenius relation. ► Solid-solid transition of glycerol within crystal phase was discovered. ► A broad melting observed in a temperature range suggests crystal heterogeneity.