An ionic conductivity accelerometer comprises a layer of an ionically conductive material such as rubidium silver iodide (RbAg.sub.4 I.sub.5) deposited on an electrically insulative substrate with spaced electrodes in contact with the layer. The ionically conductive material may be mixed with an electrically insulative, chemically inert material such as quartz wool in order to alleviate susceptibility to cracking.