A variety, called ruby blende, is cryftal-
lized on calcareous fpar, and is of a beau-
tiful tranfparent red.
Another variety is called pigeon necked
blende, from its iridefeent hues.
Red blende, minutely cryflallized on
fluor.
The blende? generally produce above
forty per cent of zinc, fometimes with iron,
lead, or copper, and are frequently iiv Hungary
and other plages, auriferous,
Zinc* is ali a found in the form of lapis ca-
laminaris. This native oxyd occurs of va-
rious colours, brown, re.ddifh, and blueifh
brown, yellow, waxy, green, white, ftala£ti-
tic, porous, &c. It is found in nodules, and
often clothes calcareous fpar, which it
• Native zinc is laid to Lave occured oflce : but after
making every inquiry, and not having been able to fee the fpe-
cinfieq, I feel w-arraat-ed in con eluding,.from qn intimate aCr
quaintance with the mine which is faid to have produced it,
that it is improbable, and wholly a miltake.
foon
foon decompofes. I have iztvi fragments of
calcareous fpar, coated with calamine: a
fufficieftt proof of the recent formation of
the latter.
It is fometimes in an ochreous date, combined
with ferruginous matter, but the
compact is the heft j and it is moft
efteemed when of a waxy colour. Sometimes
there are tranfparent tabulated cryftals,
and it is frequently botroidal, or in the
form of grapes, and alfo ltaladlitic. The
fnow white is mamellated, and is extremely
rare. It feldom occurs coating
fluor, but often decompofmg calcareous fpar,
and is frequently attendant on blende.
Calamine generally contains above hxty
per cent of zinc, with fome iron ; and affumes
various appearances, fometimes effervefeing
with acids, and phofphorefcent.
To the eaft of Caftleton is the place called
Red Seats, where are feveral rake veins
h 2 containing