The Great Pyramid of Giza was originally covered with casing stones made of Tura limestone.
Tura limestone was a fine, bright white limestone quarried from the Tura quarries on the eastern side of the Nile. Builders transported it by river and used carefully dressed blocks to create the pyramid’s smooth outer surface. When complete, the casing reflected sunlight and made the monument appear far more polished and luminous than the rough core visible today.
Most of the Great Pyramid’s internal mass consists of locally quarried limestone from the Giza plateau. The exterior casing was a higher-quality imported stone, while granite from Aswan was used in important interior features such as the King’s Chamber and its surrounding structures.
Much of the Tura casing was removed over many centuries, particularly for reuse in Cairo and after damage from earthquakes. A small number of casing stones remain near the base. Nummulitic limestone is a useful distinction: it describes much of the local Giza limestone, whose fossil content includes coin-shaped nummulites, but it was not the standard answer for the pyramid’s original outer casing.