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BOOK IV
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69
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obsidianus since Pliny writes as follows concerning glass. Obsidianus is
classified as a glass because of a similarity to a stone found at
Obsidius, Ethiopia, which is very black and sometimes transparent. It
has a dense appearance and reflects a dark shadowy image like a mirror.
They make many gems from it and the statue of Saint Augustus was cut
from the massive dense material as well as the four elephants in the
temple of Concordia which was consecrated by a miracle. Tiberius
Caesar, when placed over Egypt, sent back an obsidian statue of
Menelaus that came into his possession, to the priests of Heliopolis.
This shows the ancient origin of the material that is now falsified
with glass. Xenocrates writes that lapis obsidianus occurs in
India; Samnium, Italy; and near the ocean in Spain. Pliny, when writing
about this mineral, says that it comes from India.7
I
shall mention the places where this bituminous earth occurs. It is
mined in that part of Britain or Albion which we call Scotland because
of the Scotch Germans who emigrated there. It is found most abundantly
about twenty miles from Edinburgh on the Deisert heath at a place they
call Carbon. Some of this material burns as I have described elsewhere.
Solinus writes that jet is also found in Britain. The hard variety that
the Romans called lapis obsidianus is mined in northern Spain.
Even today they still make statues from this material and many of these
have been brought to us from Galicia by travellers. It is mined at
Sion, France and in Lower Germany, especially near Leodiensis. The hard
material from the latter locality is used to make the best beads with
which we calculate prices. It is found in Lower Germany at Aquisgranus
and in Greater Germany in many places, especially in Saxony at the town
which is named Oberbach because of the white poplars, about twenty
miles north of Μ under. It is found in Misena in a mountain famous for
its coal, two and one-half miles from Zuicca. There the miners worked
the earth to a depth of six feet and then having enlarged the diggings
they discovered a vein of soft coal almost eighteen feet thick when
completely exposed. Below this was a very dense rock and below the rock
a second vein of coal so hard they have given it the name "pitch" which
it resembles in color and luster.8 Below this vein bituminous cadmia was
found and below that aluminous pyrite, pure copper and coal. There are
burning mountains in certain localities and the coal that feeds the
fire is changed into a black powder when earth falls into the fire and
extinguishes it. Such a place is found along the distant Black river
that flows through the solitudes of Africa where jagged, burnt-out
rocks jut from the river. Pliny writes that Suetonium Paulinum was his
authority for the above statement. This same genus of bituminous earth
is found five miles from Dresden, Misena, on the road to Freiberg. It
also occurs at three places
7 These descriptions refer to the volcanic glass called obsidian and not to a bituminous material or jet.
8 This probably refers to anthracite coal.
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