The half-life for double beta decay of Te 130 is determined to be (2.83 + or - 0.30)10 21 years from an analysis of xenon and tellurium in the tellurides from Kalgoorlie, Australia. The use of high sensitivity noble gas mass spectrometry to measure small amounts of the Xe 130 formed from the double beta decay of Te 130 makes possible a new age determination method for hydrothermal deposits rich in tellurium. Three telluride samples from different geographic locations have been dated by the Te 130 -Xe 130 method and the ages obtained are consistent with the geologic age estimates.