Four lepidolites of known age and location were etched in acid and observed microscopically for fission tracks. Only one had naturally occurring fission tracks; the rest had none. The ability to see fission tracks seems to depend upon telling them apart fro other naturally occurring phenomena, plus the facility to etch them to the proper size for recognition. After etching, the lepidolite containing fission tracks was observed to have approximately 100 tracks per cm
