230 SIENITE. 
and it has been discovered in some of the western and 
northern parts of Great Britain. 
S62. SIENITE is a rock composed chiefly of felspar (110) 
and hornblende. Its colours are usually reddish and black. 
Some varieties of it contain quartz (76) and mica (123), 
with but little hornblende. In these the colours are various. 
Although this is a less abundant rock than any of 
those that have yet been mentioned, it occurs, in 
great abundance, at Mount Mado, in the island of 
Jersey. There are extensive quarries of it in that 
mountain, not only for the use of the island, but for 
exportation to England, and other distant countries. 
The cliffs, for a long space, and an elevation of a hun- 
dred feet or more, consist entirely of sienite, in large 
masses, which are apparently uninterrupted by a single 
fissure. Shafts for columns of considerable length 
have been taken from these quarries ; and, were the 
demand sufficient to call for new openings, it is ima- 
gined that columns of twenty feet and upwards in 
length might be raised. The felspar is of a flesh co- 
lour, and the stone is capable of a beautiful polish. 
A somewhat similar kind of sienite is found at Grande 
E-oque, in the island of Guernsey, in large masses, 
which are quarried for building stones. Sienite also 
occurs in some parts of Scotland and Derbyshire ; in 
Saxony, Hungary, the island of Cyprus, and Egypt- 
Its name has been derived from that of the city of 
Syene, in Upper Egypt, where it is found in great 
abundance. 
Sienite was much used by the ancients in ornamental 
architecture. What was called the red granite of 
Egypt (for this rock has usually been considered a gra- 
nite) furnished numerous magnificent obelisks and co- 
lumns, of a single piece, which have been much admired 
in Rome and other places. The ancient artists some- 
times cut this kind of stone into statues, vases, monu- 
mental and other works. The celebrated column in 
Egypt, upwards of ninety feet high, and known by the 
name of Pompey's Pillar, is formed of sienite. 
