antimony - Sciencemadness.org

THE GEOLOGICAL OCCUERENCE OF ANTIMONY ORES. 53
tions, which have transformed the alberese (a variety of Eocene calcareous
rock found in Tuscany) in part to gypsum and anhydrite.
It is not quite certain whether the antimony deposit has any genetic
relation with the sulphurous vapour. (Probably C.)
At San Martino, Tuscany, cinnabar is found accompanying the
stibnite.
At Monte Auto there is a peculiar occurrence of antimony ore,
which is found in great blocks distributed in a black clay containing
no other kind of rock except occasionally masses of dolomite, impregnated
with stibnite. (D.)
At Siena, the Cettine di Cotorniano mine is opened in a vein of
blackish quartz-like rock, in which, near the surface, oxide of antimony
is found, changing, however, to the sulphide at some depth. (A.)
At Rosia, the stibnite is accompanied partly by calcite and partly
by quartz.
At Su Suergin, in Sardinia, the deposits occur at the contact of
the Ehsetic limestone with Permian slate. Antimony glance, accompanied
by pyrites, is also found in the mica schist. Traverso gave the
opinion that these deposits are of sedimentary origin rather than of
vein formation. (E.)
ENGLAND.
Antimony ore is found very sparingly in Cornwall.
SPAIN.
Veinlets of quartz, carrying stibnite, occur generally in a belt of
metamorphic schists and shales, their strikes being between W. 10° S.
E. 10° N. and S. W.-N.E. The shale, for a breadth of about three feet,
seems to be mineralised by veinlets of quartz with stibnite, by
pockets and impregnations of that mineral, whose walls are generally
not well denned. (A and C.)
Near Viuvela, in Malaga, native antimony is found to be impreg
nated in the clayey shales, the size of the impregnated masses vary
ing from that of an egg down to minute spangles.
Other localities that may be mentioned are Estremadura and
Badajoz, Caurel, Brollou, Orense.
PORTUGAL.
In the district of Evora, antimony ore occurs in quartz lodes at the
contact of Palaeozoic beds and granite. (A.)