Rose-coloured Syenite of Egypt, 263 



an homblendic granite, or as a rock forming a passage from 

 the family oi granite to that of syenite. 



From the interesting researches of Messrs Russegger* 

 and Newboldt on the geology of Egypt, it results that the 

 granite rocks occupy but a very small extent ; they show 

 themselves particularly at the cataract near Syene, and in 

 the desert where they separate the Nile from the Red Sea, 

 in the latitude of Koseir, about 26° N. 



The syenite in particular is found half a league north of 

 Syene, and according to Russegger, it extends a good deal 

 to the south of the cataract and the island of PhilsB into 

 Nubia; and it is found at Elephantine and the intervening 

 islands. From the collection of Lefevre it appears also to 

 have been met with in the Djebel Gareb and Djebel Elzede 

 (Mountain of Oil), between Koseir and Suez. 



The syenite generally disappears under a brown sandstone, 

 which according to M. Russegger is again found with the 

 same characters in Upper Egypt, in Nubia, and in Sinai. 

 This sandstone appears to belong to the lower part of the 

 chalk formation, or the Quader-sandstein : near Fatireh it 

 is covered with a white earthy chalk, having a somewhat 

 conchoidal fracture, that reposes on it in conformable and 

 horizontal strata. 



The quarries in which the ancients worked the syenite 

 have been observed by all travellers who have visited Egypt ; 

 they are principally south of Syene, and between Syene and 

 the island of Philse. The detached blocks of the syenite, near 

 the cataract, are sometimes of a spheroidal form, and are 

 separable into concentric layers; according to Newbold, 

 however, the dry and hot climate of Egypt preserves the 

 granite rocks much more from decomposition than the 

 climate of India. 



M. Russegger remarks, that near the cataract, the blocks 

 found in the river, or at a small distance from it, are covered 

 with a very thin and brilliant substance resembling blackish 



* Russegger, Reisen in Eoropa, Asien, and Afrika, U. S. W. Stuttgart, 8vo. 

 t ioc. tit. 



