The Rosetta Stone is an inscribed basalt block.

The Rosetta Stone is an inscribed basalt block, discovered by French soldiers in Egypt in 1799. Carved in 196 BCE, the same text is written on it in Ancient Greek, hieroglyphs, and demotic (an everyday Egyptian script). In 1822, French linguist Jean-François Champollion used the inscriptions on the stone to work out how to read hieroglyphs, which until then had been impossible to decipher.