Amratian, or Naqada I, is an era in Nubia during Predynastic Egypt that lasted from c.4000-3500 BCE. See: ...
Middle pre-dynastic period, 3550 to 3400 BCE, also called Naqada IA and IB
of, pertaining to, or belonging to the predynastic Chalcolithic culture that flourished in Upper Egypt about 3800 b.c., characterized by the working of raw gold, the use of copper, and the burial of the dead in shallow graves.