The Rosetta Stone uses Egyptian for its hieroglyphic and demotic sections, alongside Ancient Greek.
The stone was created in 196 BCE during the Ptolemaic period. Its decree was issued in the name of Ptolemy V and repeated in three scripts: Egyptian hieroglyphs, Egyptian demotic, and Greek. Demotic was a later, more cursive form of the Egyptian writing tradition.
The Greek text was crucial because scholars could read it, while the Egyptian scripts had become undeciphered. Jean-François Champollion used the parallel inscriptions, along with other evidence, to help decipher hieroglyphs in the 1820s.
Egyptian is not the same language as Coptic, although Coptic is its latest historical stage. Coptic was written mainly with a Greek-based alphabet supplemented by several Egyptian signs and remains important in the Coptic Orthodox Church.