The concept of 'speromagnetism' in insulators describes a state of matter in which the antiferromagnetic exchange interaction between neighbouring magnetic ions is frustrated, leading to a random, isotropic spin structure. The detection of speromagnetism has relied heavily on applied-field Mossbauer spectroscopy. The authors consider the Mossbauer data on three ferric insulators said to be speromagnetic, and find that they may be most simply modelled in terms of antiferromagnetism.