Earth's Oldest-known Rock

The white bands in this 3.96-billion-year-old gneiss consist of quartz and feldspar, two minerals common in granite. Their presence tells us the gneiss was metamorphosed from granitic rock contained in Earth's earliest continental crust.

Group: Metamorphic
Catalog Number: 116542.0001
Gift of S. Bowring
Locality: Northwest Territories , Canada