The bird pendant is of the type that Jessica Rawson describes as becoming widespread in the Western Zhou period. See, J. Rawson, Chinese Jades from the Neolithic to the Qing, British Museum, 1995, p. 227, fig. 1.
The cicada pendant is similar to one dated to the Western Zhou period of slightly smaller size (3 cm. long) which was excavated at Baicaopo, Lingtai, Gansu province, and is now in the Gansu Provincial Museum. See Gu Fang, The Complete Collection of Unearthed Jades in China, vol. 15, Beijing, 2005, no. 69.