A black basalt slab was found by a soldier in 1799 that contained fragments of pages written in three diffe

A black basalt slab was found by a soldier in 1799 that contained fragments of pages written in three different scripts: Greek, Egyptian hieroglyphics, and Egyptian demotic. Two decades later, French Egyptologist Jean Fran�ois Champollion was able to decipher the hieroglyphics using his knowledge of Greek as a guide, and the language and culture of ancient Egypt was suddenly open to scientists as never before. What was the name of this artifact?