We have combined low- and high-temperature measurements for identifying possible mineral transformations (e.g., maghemite to hematite, titanomaghemite to magnetite) in thermomagnetic runs (magnetic susceptibility vs. temperature) for a weathered metapelite xenolith sample from Zhouba, North China. The results show that lab-induced saturation isothermal remanence magnetization (SIRM) changes observed between room temperatures and 25°C, and between 280 and 380°C are caused by the remanence unblocking of titanomagnetite (a physical process) and the inversion from maghemite to hematite (a mineralogical phase transformation), respectively. Furthermore, the significant increase of susceptibility after 500°C is interpreted as the mineral exsolution of magnetite from titanomaghemite. Thus, the magnetite-like Curie temperature revealed by қ-T curves is caused by the neoformation of magnetite.