The Iola register. [volume] (Iola, Allen County, Kansas) 1875-1902, 1884-10-17
Agates.

tef known as "Scctcn peoples, WHICH.
although small compared with those
found elsewhere, are yet unequaled IL
the variety and beauty Of their colors.
Scottish pebbles are found chiefly at
Kinnoul Till, near Perth. on the shore
near Montrose, at Dunglass. and at
Burn Aune, near Galston. Ayrshire,
but whether they occur on the shore or
in river gravels. they have been all
prev ously washed out of trap rocks.
The pebbles. cut by Edinburgh lapi-
diaries, are used in the manufacture of
Scottish jewelry. The chief seat of the
agate industry of the world. however.
is at Oberstein, in Rhenish Bavaria,
where it has been carried on for centu-
ries. 1t arose there naturally enough.
owing to the presence IN the volcanic
rocks of the neighborhood of an abund-
ance of fine agales; but it has contin-
ued and extended long after those
rocks have ceased to yield, or at
least to be mined for. the raw material
of the industry. The agate Guarries of
Oberstein were abandoned owing to the
discovery, fully q half century ago, of
rich supply of these stones IN the river
gravels OF Uruguay. Some German
workers in agate, who had emigratea
to that region, noticed the courtyard of
a farmhouse paved with pebbles that re-
minded them OF the agates o; their ma
tive Uberstein Specimens were ac-
cordingiy sent home and cut, and the
surmisc proved correct. since that
time there has been a regular export of
agate nodules from Uruguay to Ober-
stein, where they have long formed the
stable material used in the agate mills.
These brazilian agates," as they are
called, when brought to Germany, are
arranged in lots and sold by auction.
stones of ordinary quality bringing, it
it is said. not more, usually, than fifteen
shillings per hundredweight. ''oer-
man agates" are thus, forthe most part.
Amer.c stones cut and polished at
Obersteiu. The extent of the industry
has greatly increased with this Access
sion of fresh material, and a
few years ago there were no
fewer than 153 agate mills, working
IA grindstones, and giving employ
ment altogether to about three
thousand persons. lheapness OF labor
and plentiful supply of water-power
had much 10 do with the continuance
of this industry ut Oberstein. The
labor is both ill-paid and severe. The
agate worker, says Professor Rudler,
who some years ago visited The mines
and mills, lilies upon a low wooden
grinding-stool, specially constructed to
fit the chest and abdomen. leaving the
limbs free; the hands are engaged IN
holding and grinding the agate. while
the feet are firmly pressed against short
stakes or blocks of wood screwed into
the floor. the reaction enabling the
grinder 10 press the agate with much
force against the moving milestone.
The friction thus produced causes the
agate to glow with a beautiful phos
pnorescent light. and red carne!ians
under this treatment look, it is said, rs
if they were red-hoI, The millstones
are of red sandstone, measure five feet
in diameter, and generally make three
revolutions per second. The liner
aeates are sliced by means of steel
wheels and diamond or emery powder.
but the cCarser stones are simply
Clipped into shape aud ground. After
ward they are polished on rotating
cylinders of wood or lead covered with
moistened tripoli."
The ingenuity of the agate worker is
not confined merely to cutting. carving
and polishing his material into all man
ner of shapes. He has also succeeded
in varying its color by artificial means.
The layers composing an agate differ
considerably in porosity. those that are
transparent, for example, being less
porous than Opaque layers. Some. in
deed, seem to be altogether impervious
ut ordinary temperature and pressure;
and agate workers both at Oberstein
and in India have awaited themselves of
this popularity in applying their STAIN
inc processes. A suitable agate, after
being thoroughly dried, is immersed in
q mixture of honey and water, or i'll
olive oil, and is kept thus for at least
three 6ays, exposed to a moderate
heat. 1t is then washed, dried, and
put into a vessel containing enough
sulphuric acid to cover it. The vessel
is thereafter exposed to gentle heat
for varying number of hours, when
the porous layers are found TO have be-
come much darker in color. The rea-
son OF this is that these layers. having
become saturated with the syrup or
oil, are acted upon by the sulphuric
ACID, which decomposes the sugary
or oily constituent and forms in its
place a deposit of carbon. 1t Is in thus
way that banded agate is converted
into the ONYX, with its black and white
layers. used in the productions of
canoes and intaglios. Exposure to
strong sunlight was long ago found to
give reddish tint to gray-colored
agates, and this suggested the burning
of such stones SO as to convert them
into carnelians. At Oberstein. likely
stones for this purpose are first dried
thoroughly, then saturated in sulphuric
acid, and afterward exposed in an
earthenwarc crucible 10 real heat.
They are allowed 10 cool slowly. and
are then seen to be of 4 bright, red
col +. Not content with initiating the
rarer natural varieties of agate. such
as ONYX and carnelian, German manu-
facturers have taken 10 staining agates
blue and all sorts of colors unknown in
the natural stones. Aniline dyes, as
unnatural as they are fugitive, have
also been lately used for agate STAIN
ing. Its possibletnat the stones them
serves may yei be ;rtiiic.ally produced.
-Erchapge.