_ agates rhe a Sicily has so gong. been ce 
This fo | 
Dr. Daubeny on the Geology of Sicily. 237 
jt is probable that the latter constitutes the softest variety 
of the Palermo limestone, and that the hardest may be seen iu 
the marble of Castronuovo, employed in the columns of the 
Palace at. Caserta, near Naples, and in on great staircase of 
the Convent of San Martino near Palerm 
The formation in general is, however, best marked by the 
beds of ‘chert, with which it is {accompanied ; these occur at 
Monti Giuliano near 'l'repani;* at Termini,. ‘and i ins 
the hills near Palermo,—others, as the Monte Pelegrino, being 
entirely destitute of them 
chert presents several pepatifal varieties, as. will be 
andevseadt when I remark that the Sicilian jaspers and 
agates are derived either directly from thence, or indirectly 
from the rolled masses in the valleys, or on the sea-shore, 
— this rock appears to have shales ished... « 
se beds have sometimes a’ brecciated or a conglo al . 
fier ‘structure, whilst at others, the siliceous matter com 
bined with a portion of alumine, ‘and just enough of lime to 
cause a feeble action with an acid, forms stripes.diverging in 
all directions, the interstices of which are filled up wit 
—— lighter coloured and softer variety of e ‘same 
materi 
The jaspideous beds are cher red or yellow, the two va- 
rieties often occur together, and are penetrated by veins of 
pure crystalline quartz, thus 5s those eo 
ebrated. 
onis also marked by the occurrence i it of a 
pulvemlent sue earth, which, by analysis, is found to con- 
peop ys weight of ma “ = ms in a el 
f phosphorescin vivi on live coals, it resembles the 
re beds ma mses in the magnesian: lime- 
stone near Buda, and ra Beudant has already noticed. 
In Hungary, this powdery substance is accom 
and perhaps derived, from, beds of a magnesian liméétone, 
with a harsh gritty feel, which, when — to the weather, 
- Formerly Mount Eryre, famous for the tower A of Venus. It is one 
of the loftiest mountains of Neptunian origin. height is stated by 
cy fees 
} The agates of Sicily were much p n among the ancients 
indeed, it i is well known that this stone soit its name. om Actes 
a river in Sicily. 
