After 5400 s, at T = 90 °C, the anisotropy begins to develop, and the equatorial values of B sharply decrease, indicating the continued evolution of bassanite crystals (Fig. , stage II and III). By 9600 s, when T = 90 °C, the meridian and equatorial B values reach their plateaus. After 9600 s, as the temperature gradually decreases to T = 35 °C, the meridian B remains relatively constant.