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Porcellanite or porcelanite, is a hard,
dense rock
somewhat similar in
appearance to
unglazed porcelain. It is
often an
impure variety of
chert containing...
-
constituent mineral in a type of thermally-metamorphosed rock
called porcellanite.
Mullite is
present in the form of
needles in porcelain. It is produced...
- and
porphyritic Porphyritic rhyolite Pyroclastic Rhyolitic tuff or
breccia Vesicular Pumice Amygdaloidal None
Vitreous (Gl****y)
Obsidian or
porcellanite...
-
durable flint,
porcellanite,
which is
found at the foot of the
eastern scree slope of the mountain.
Three small outcrops of
porcellanite can be seen on...
- and
often polished. The
products of axe
factories next to
sources of
porcellanite, an
especially good stone, were
traded across Ireland; the main ones...
- back as the
Mesolithic period. A
Neolithic stone axe
factory featuring porcellanite stone is to be
found in Brockley, a
cluster of
houses within the townland...
- as:[citation needed]
Great Langdale,
England (tuff)
Rathlin Island,
Ireland (
porcellanite) Krzemionki,
Poland (flint)
Neolithic flint mines of Spiennes, Belgium...
-
Neolithic period.
Excavation of one of the
cairns revealed a
polished porcellanite axe,
which may have
originated from the
Tievebulliagh axe factory, some...
-
Rocks from the
Monterey formation consist mostly of
silicate shales and
porcellanite (silica
derived from
fossil plankton in an
intermediate to deep-water...
- non-volcanic sediments.
Doleritic sills in
siltstone and mudstone. A
Porcellanite deposit was
quarried by the Māori but note that some
deposits may be...
