Geolojy of Mount Sinai and adjacent Countries. 201 



Sal, eruptive and crystalline rocks abound ; consequently 

 their detritus washed down that valley by heavy rains might 

 convey small quantities of ^gold, which may possibly be de- 

 tected in the gravel or sand, near the mouth of Wadi Sal, 

 behind Dahab. 



Hcematite, or red iron ore, has been met with in round 

 masses in the Sinaic district. Large and beautiful crystals 

 of quartz^ or rock crystals, occur in the mountains not far from 

 the present Convent. In Wadi Sheikh, Burckhardt describes 

 a range of low hills of a mineral called Tafal, principally 

 composed of felspar from granite^ and resembling pipe-clay ,• 

 it is brittle, and leaves a yellow colour on the fingers. The 

 Arabs use it for soap, and for taking stains out of cloth. He 

 also observed another range of Tafal hills, after the defile 

 (at El Bueb) towards the west, in Wadi Firan. 



Rock-salt is very abundant in many places ; this, together 

 With sulphur, prevents many of the springs from being of use 

 to the traveller. 



Gypsum is also frequent, as well as selenite or crystallized 

 sulpliate of lime, in certaiti argillaceous beds along the west 

 coast. 



Carbonate of soda, commonly called Natron, " may be found 

 ^t Tur, and in the vicinity of Sherm ; but we do not find it 

 accumulated in any considerable quantities, only some efflor- 

 escences of it in places where the calcareous soil has been 

 impregnated with marine salt''* 



Saltpetre or nitre is seen incrusted on the surface of the 

 «arth, " in a valley between Mount Sinai and Suez,"t and in 

 some spots in Wadi Araba. 



Besides rock crystals already mentioned, Burckhardt de- 

 scribes the occurrence of white and rose-coloured quartz : a 

 species of amethyst is said, by Pliny, to have been ** found 

 southward in Paran, whence it took the name of Paramte.''*^ 



Jaspers and Egyptian pebbles occur in the gravel of the 

 desert El Tyh, and near the extremity of the Gulf of Suetc. 



* Kitto'a Phys. Geog. of the Holy Land, p. 103, 

 t Phillips' Mineralogy, p. 189. 

 I KittOf p. 111. 



