(Image: Mohammed Salem, Pixabay)
The term granite broadly applies to any holocrystalline quartz-bearing plutonic rock, in which quartz makes up 10 to 50% of the felsic components, the alkali feldspar/total feldspar ratio is between 65 to 90%, and the modal concentration of mafic minerals is less than 10% (hornblende, biotite). Grain size of the minerals components generally range from 1 millimeter to many centimeters..
Granite is widely distributed in Egypt and occurs in large deposits at Aswan, in the Eastern desert, the Sinai, and to a smaller extent in the Western desert (see map). In the Aswan region the granite deposits consist of both the monumental red and monumental black varieties. Both of these varieties of granite were quarried by the ancient Egyptians from the Early Dynastic to the Roman period. The monumental red granites are very coarse- to mainly coarse-grained and pinkish to occasionally reddish in colour. They can sometimes be gneissoid and porphyritic (phenocrysts up to 4 cm), and can be found to be gradational with the monumental black granite variety. The monumental black granites are coarse- to mainly medium-grained, dark gray to nearly black in colour, but they are mainly granodioritic. They are commonly porphyritic (phenocrysts up to 3 cm) and gneissoid, and can be found to be gradational with the monumental red granite variety. The phenocrysts vary from white to pink in colour and may be largely or entirely absent in some specimens. Polished rock slab images of monumental red and monumental black varieties can be seen at the Ancient Egyptian Quarries website (section 4). During the Late Dynastic and Napatan-Meroitic periods a dark gray (nearly black on weathered surfaces), medium- to coarse-grained granite gneiss to granodiorite gneiss was used. These were quarried on the south bank of the Nile at Daygah, Sudan (see map). Polished rock slab images of these rocks can be seen at the Ancient Egyptian Quarries website (section 7). Both the granite deposits of Aswan and Daygah are of Precambrian age. A number of smaller quarries are are also known (Lucas and Harris, 1962).
Granite was used by the ancient Egyptians for building, generally as a lining material for chambers and passages, interior structure of temples, for door frames, and as facing stones, from the Early Dynastic period onwards. In most instances granite used for these purposes was a coarse-grained red variety from Aswan (monumental red granite), and to a much lesser extent a grey to black granite (monumental black granite) was used. During the Predynastic period granite was used to a very small extent chiefly for making vases and bowls. As the occurrence of granite increase as a building material its use for bowls and vases also increased. This seems to correspond to the increased use of copper tools by the ancient Egyptians (Lucas and Harris, 1962). During the Early Dynastic period onward it was used for sarcophagi, and during later periods it was used for statues, obelisks, stelai, and other objects.
Lucas, A. & Harris, J.R. (1962) Ancient Egyptian materials and industries. E. Arnold, London, 523 p.
Links to examples of granite usage
f) Misc objects