Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1884-12-06
mtsrellaneDns.
Agates.
WHERE THEY ARE FOUND AND How
THEY ARE WORKED.

Scotland is famed for its agates. better
known as Scotch pebbles" which. al
though small compared with those found
elsewhere, are yet unequalled in the va
riety and beauty of their colors. Scottish
pebbles are found chiefly at Kinnout hill.
near Perth, on the shore near Montrose.
at Dunglass, and at Burn Anne, near
Galston, Ayrshire, but whether they occur
on the shore or in the river gravels, they
have been all previously washed out OF
trap rocks. The pebbles, cut by the Ed
inburg lapidaries, are used in the manu-
facture of Scottish iewelry. The chief
seat of the agate industry Of the world.
however, is at Oberstein, in Rhenish Ba-
varia, where it has been carried on tor
centuries. 1t arose there naturally enough,
owing to the presence in the volcanic
rocks of the neighborhood of an abun-
dance of fine agates but it has been con-
tinued 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 quarries OF Oberstein were
abandoned owing to the discovery. fully
half a century ago, of rich supply Of
those stones in the river grayels OF
4 uruguay. COtuc WI hCiS III oSoOC
who had emigrated to that region, noticed
the courtyard of farmhouse paved with
pebbles that reminded them of the agates
of their native Oberstein. Specimens
were accordingly sent home and cut, and
the surmise proved correct. Since that
time there has been regular export of
agate nodules from Uruguay to Oberstein,
where they have long formed the staple
material used in the agate mills.
The Brazilian agates," as they are
called, when brought to Germany. are ar
ranged in lots and sold by auction. stones
of ordinary quality bringing, it is said, not
more. usually, than Is shillings per hum
bred weight German agates" are thus
for the most part, South American agates
cut and polished at Oberstein. The ex-
tent of the industry has greatly increased
with the accession of fresh material, and a
few years ago there were no fewer than
1873 agate mills, working 724 grindstones,
and giving employment altogether to
about 5000 persons. Cheapness of labor,
and plentiful supply of water power,
had much to do with the continuance of
this industry at Oberstein. The labor is
both i'll paid and severe. 1.-The agate
worker" says Prof. 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 and the
hands are engaged in holding and grind
ing the agate, while the feet are firmly
pressed against short stakes or blocks of
wood. screwed into the floor, the reaction
enabling the grinder to press the agate
| s,nnnh fnroa az tho y,nnuipor mill
stone. The friction thus produced, caus-
es the agate to glow with beautiful
phosphorescent light, and red carnelians
under this treatment look, it is said, as If
they were red hot. The millstones are
red sandstone, measure five feet in diam
eter, and generally make three revolutions
per second. The finer agates are sliced
by means of steel wheels, and diamond
or emery powder, but the coarse stones
stones are simply Clipped into shape and
ground. Atterward they are polished on
rotating cylinders of wood or lead. cover
ed with tripoh.
The ingenuity of the agate worker is
not confined to merely cutting, carving
and polishing his material into all manner
of shapes. He has also succeeded in vary
ing its color by artificial means. The lay
ers composing an agate differ considera-
bly, in porosity, those that are transparent
for example. being less porous than
opaque layers. Some, indeed, seem to
be altogether impervious at ordinary tenn
perature and pressure; and agate workers
| both at Oberstein and in India have
availed themselves of this peculiarly in
applying their staining processes, A
suitable agate. after being thoroughly
dried, is immersed in a mixture of honey
and water or in olive oil, and is kept thus
| for at least three days exposed to mod
crate heat. 1t is then washed, dried and
put into a vessel containing enough sui
phuric acid to cover it. The vessel is
thereafter exposed to gentle heat for a
varying number of hours, when the po-
rous layers are found to have become
much darker in color. The reason of this
is that these layers, having becoume satu-
rated with the syrup or oil. are acted
upon bv the sulphuric acid, which decom
poses the sugary or oily constituent and
forms in its place deposit OF carbon. 1t
is in this way that banded agate is con-
verted into the onyx, with its black and
white layers, used in the production of
canoes and intaglios, Exposure to strong
SuullUHl WAS lOHU ago louIlu 10 give u Teu-
dish tint to gray colored agates, and this
suggested the burning of such stones so
as to convert them into comedians. At
Oberstein, likely stones for this
purpose are first dried thorough
ly, then saturated in sulphuric acid,
and afterwards exposed in an earth
enware crucible to red heat. They are
allowed to cool slowly, and are then seen
to be of bright, red color. Not content
with initiating the rarer natural varieties
OF agate, such as onyx and cornelian,
German manufacturers have taken to
staining agates blue and all sort of colors
unknown to the natural stones. Aniline
dyes. as unnatural as they are fugitive,
have also been lately used for agate stain
ing. 1t is possible that the stones them
selves may yet be artifcially produced
Indeed. according to King ("Natural His
tory of Gems"O, Florentine anatomisl
long ago accomplished, this feat, although
unfortunately the secret died with him
He is said TO have petrified human viscers
into real agates. lin the hospital of San
Spirto may be inspected still by the in
credulous, says King. "a table top made
up of hearts, lungs, livers. etc, thu.
agatized into one large slab-meet board
for banquet of vampires !" Organic
remains in agates are not unknown, fol