was the essential key to the modern understanding of ancient Egyptian literature and civilisation. The term 'Rosetta Stone' is now used to refer to the essential clue to a new field of knowledge. Description The Rosetta Stone is listed as "a stone of black granodiorite, bearing three inscriptions ... found at Rosetta" in a contemporary catalogue of the artefacts discovered by the French expedition and surrendered to British troops in 1801. At some period after its arrival in London, the inscriptions were coloured in white chalk to make them more legible, and the remaining surface was covered with a layer of carnauba wax designed to protect it from visitors' fingers. This gave a dark colour to the stone that led to its mistaken identification as black basalt. These additions were removed when the stone was cleaned in 1999, revealing the original dark grey tint of the rock, the sparkle of its crystalline structure, and a pink vein running across the top left corner. Comparisons with the Klemm collection of Egyptian rock samples showed a close resemblance to rock from a small granodiorite quarry at Gebel Tingar on the west bank of the Nile, west of Elephantine in the region of Aswan; the pink vein is typical of granodiorite from this region. The Rosetta Stone is high at its highest point, wide, and thick. It weighs approximately . It bears three inscriptions: the top register in Ancient Egyptian hieroglyphs, the second in the Egyptian Demotic script, and the third in Ancient Greek. The front surface is polished and the inscriptions lightly incised on it; the sides of the stone are smoothed, but the back is only roughly worked, presumably because it would have not been visible when the stele was erected. Original stele The Rosetta Stone is a fragment of a larger stele. No additional fragments were found in later searches of the Rosetta site. Owing to its damaged state, none of the three texts is complete. The top register, composed of Egyptian hieroglyphs, suffered the most damage. Only the last 14 lines of the hieroglyphic text can be seen; all of them are broken on the right side, and 12 of them on the left. Below it, the middle register of demotic text has survived best; it has 32 lines, of which the first 14 are slightly damaged on the right side. The bottom register of Greek text contains 54