436 
NATURAL HISTORY OF AFRICA. 
with in Africa are the Ava?iturine, which is found 
in Egypt, and the rock crystal of Tunis. 
8. Wood Stone.— This mineral is already men- 
tioned as occurring imbedded in the sand of the 
desert. 
9. Calcedony and Cornelian. — Both these semi- 
pellucid stones are found on the banks of the Nile, 
in Upper and Lower Egypt. 
10. Agate. — It is found to the eastward of 
Cairo. 
i 1 . Common jasper. — It occurs in veins of con- 
siderable thickness in clay slate in Upper Egypt. 
12. Egyptian Jasper. — This beautiful mineral, 
which is peculiar to Africa, occurs loose, and very 
abundantly in the sandy desert between Cairo and 
Suez : also in other parts of Lower Egypt, where 
it is said to occur, imbedded in a species of conglo- 
merate. 
13. Prehnite. — This beautiful species of the ze- 
olite family is found in veins that traverse granite, 
in the country of the Namaquas, to the north of 
the Cape of Good Hope. 
14. Actynolite. — It occurs in alpine valleys in 
Upper Egypt, along with epidote. 
15. Hornblende. — It is abundantly imbedded 
in the syenite and greenstone of Upper Egypt. 
16. Amianthus. — Beautiful blue and yellow co- 
loured amianthus are found near Hardcastle* on 
the Orange river, in Southern Africa. Specimens 
i 
