210 PROCEEDINGS OF THE GEOLOGICAL society. [Jan. 19, 
Near the small town of Kirn, between Obersteim and Kreuznach, 
coal is found, but of a very inferior and clayey quality. I had no 
opportunity of visiting the works, or of ascertaiming its position with 
regard to the conglomerate of Oberstem and the New Red or Bunter 
Sandstein lower down the valley; I am therefore unable to say 
whether this conglomerate is to be considered as forming the base of 
the Carboniferous, or of the New Red system; it is however suc- 
ceeded lower down the valley by overlying sandstones and blue shales, 
which, being broken through and overturned in various places, parti- 
cularly between Kirn and Martinstem, by numerous outbursts of 
porphyry, greenstone and other igneous rocks, extend into the great 
basm of Mayence, where between Kreuznach and Weinheim they 
form the base, still penetrated m numerous places by trap rocks and 
porphyries, of the overlying tertiary formation so abundant in organic 
remains, attributed to the miocene period. 
In the immediate vicinity of Oberstein, this conglomerate, which is 
cemented together by a hard red matrix, and dips at an angle of 
30° to the S.E. or E.S.E., contains several veins of a kind of imper- 
fect agate or chalcedony, which were at first pomted out to me as the 
agate quarries (Achat Gruben) of Oberstein. These quarries occur 
low down in the series, near the junction of the conglomerate with 
the underlying amygdaloid, and are almost on a level with the bed 
of the river. This agate vem varies in thickness considerably, and 
runs in a nearly straight direction from N. toS. or N.N.E. to S.8.W.,; 
and with a dip of nearly 70° or 80° to the E. or E.S.E., and nearly 
at right angles with the dip of the strata. This siliceous substance, 
improperly called agate, bemg in fact a simple chalcedony, is of a 
honey-yellow colour, sometimes approaching slightly to red; the vem 
occasionally separates so as completely to envelope the pebbles of the 
conglomerate; im other places it spreads out into large irregular 
masses, and sometimes passes through the pebbles and the red matrix 
together, thus proving that it must have been deposited subsequently 
to the consolidation of the conglomerate rock, or Flotz-Gebirge as it 
is here called; this however can hardly be seen in the hand-speci- 
mens which I obtained. In one portion the vem becomes nearly 
black or bluish grey, and is then apparently more compact. Some 
specimens occur showing how the original fissure in the conglomerate 
rock was filled up by the deposition of a thin coating of siliceous 
matter on each side or wall, leaving a space in the centre where the 
mamuillated surface of the chalcedony is well-exposed. 
This stone, when submitted to the artificial processes which I shall 
presently allude to, and which the agate-workers have learned to 
apply to these substances from the Italian purchasers and artists who 
had long possessed the secret, assumes the deep red colour of corne- 
lian. The quantity of it which is obtained is not very abundant, nor 
are the pits very extensively worked. 
But:these are not the real euarries where the celebrated Oberueat 
agates are obtained. These beautiful stones come from the hills in 
the neighbourhood of Idal, about two miles distant from Oberstein, 
along the road to Saarbruck. The polishing-mills also are at Idal, 
