Melting temperatures Tm of six heavy rare earth metals are well established experimentally. Here, a close correlation is displayed between these values Tm and the de Gennes factor (ξ below), which is proportional to the product of (g − 1)2 with total angular momentum values J (J + 1). We thereby exhibit a tendency of a plot of Tm versus ξ−1 to saturate at the largest ξ, this corresponding to Gd of the six selected elements. Second, following Chikazumi’s book, it is stressed that the Néel temperatures TN of the remaining five metals display empirically a good linear correlation with . Finally, the monovacancy formation energy is briefly considered in relation to the thermal energy kBTm, the ratio Ev/kBTm being of order 10 in other known cases.