Fission-track ages determined from garnets in pegmatite and garnetiferous amphibolite from Bhilwara and Ajmer districts of Rajasthan range from 900 m.y. to 1,370 m.y. They date the time of formation of the pegmatites (about 1,000 m.y. B.P.) and the metamorphism during F1 (∼1,400 m.y. B.P.) folding in the area. The uranium content of the garnets varies from 1.76 × 10−8 g/g to 21.4 × 10−8 g/g.