Current-voltage characteristics and aging properties of modified sepiolite taken from Anatolia have been studied. Sepiolite mineral dispersed by ultrasonic methods and saturated with Fe2+ by ion-exchange has been oriented in an 11 kG magnetic field. DC measurement techniques have been applied to ribbon type samples oriented in a magnetic field. Whereas, application of these techniques to samples that have not been oriented in a magnetic field was possible because of very small and unstable current, samples oriented in a magnetic field have shown a linear change. The current-voltage studies done at different time periods have shown that sample resistance has risen in time approximately 100 times, and aging has begun. This has been evaluated as being the result of sepiolite interaction with water vapor in the medium, rather than the oxidization of the contacts. (C) 1999 Elsevier Science B.V. All rights reserved.