Disclosed are improved ceramic compositions which are useful in the formulation of microwave susceptors and to the susceptors fabricated therefrom for disposable packages for the microwave heating of food items. The compositions include certain metal salts as time/temperature profile moderators in addition to a novel microwave absorbing material and a binder. Certain metal salts can be used to dampen or lower the final temperatures reached upon microwave heating the ceramic compositions. Other metal salts can be used to increase or accelerate the final temperature reached upon microwave heating. The microwave absorbing materials comprise selected ceramics in both their native and amphoteric forms. Such useful ceramics are those with residual lattice charges or an unbalance of charge in the fundamental framework or layers such as vermiculite, bentonite, hectorite, zeolites, selected micas including Glauconite, phlogopite and Biotite and mixtures thereof. These ceramics are activated to their amphoteric form by treatment with either acids or bases. The compositions provide good heat generation and a predeterminable upper temperature limit which is higher in the amphoteric form than in their native form. The ceramic materials are common and inexpensive.