Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1884-07-31
CONCERNING AGATES.
Edinburgh seotsman.J

known as "scotch pebbles" which, al
though small compared with those found
elsewhere. are yet uncqualled in the variety
| and beauty Of their colOrs. Scottish peb-
| blcs are found chiefly at hlnnoul Hill, near
| Perth, on the shore near M0ntr0se, at Dun
| glass. and at Bum Aune. near Galston,
AYRSHIRE, but whether they occur on
The shore or In river gravcls. they
have been oil previously washed out
Of trap rocks. The pebbles cut by
Edinburgh apidaries, are used in the
manufacture OF Scottish iewelry. The chief
seat OF the agate industry OF the world,
however, is at ObersteiD, in Rhtnish Bava-
ria, where It has been carried on for cen
turtles. II arose there naturally enough,
owing 90 the presence in the volcanic rocks
Of the neighhOrhood OF an abundance OF
fine agatcs; bat il has continued aud eX-
tended long after those rocks have ceased
To yield, or at least 10 be mined for, the
raw material Of the industry. The agate
QUERIES Of Oberstein were abandoned,
owing to the discovery, fully half CEN
fury ago. OF a rich supply Of those stones
in the rIyer gravels OF Uruguay. Some
German workers in agate, who had emil
grated TO that region, noticed the court
yard of.a farmhouse paved with pobbl
native OberStein. Specimens were ac-
cordingly sent home ard cut, and the sur
mise proved correct. Since that time there
has been a regular export OF agate noduics
from Uruguay TO OberStein. where they
have long formed the staple material used
in the agate mills. These " brazilian
agateS," rs they are called, when brought
TO Germany, are arranged in lots and sold
bv auction. stones Of ordinary quality
bringing, il is said. not more usually than
15s. per hundredweigbt. German agates"
are thus for the most part south American
stones cut and polished at Obcrsicin.
Tie extent Of the industry has really
increased with this accession OF fresh
material. and few years ags there
were 10 fewer than 1873 sgate mills, work
ing 124 grindStoneS aud giving en-
plOymcnt altogether TO about 5000 per-
sons. CheapneSS OF Labor and plentiful
supply Of water-pOwer have bad much 10
do with the continuance of this industry at
OIerstein. The labor is both ill-pad ant
severe. The agate-wOrker, says Professor
RudloT, who some years ago visited the
mines and mils. hes upon low wooden
grindng-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
fOor, the reaction enabling The grinder
TO press the agate with much force
sran,st tie moving ...,..;,,,.ctone. Tue friction
thus produced causes the agate to glow
witt beautiful phosphOrescent light and
rcd caInelians under this treatment look.
IL is said, as il ~ -. mi.
miilstoRes are Of red sandstone, measure
I'VE fett in diameter, aud generally make
tiIree revolutions per second. The liner
aga;es are sliced by means Of steel wheels
aud diamond or emory powder, but The
coarser stones are simply Clipped into
shape and ground. AftWward they are
polished on rotating cylinders OF wood or
lead covered with molstenel tripOli.
The ingenuity OF the agate worker is not
confined merely TO cutting, carving, and
polishing his material into all manner OF
shapes. lie has also succeeded in varying
ITS color by artificial means. The larers
COMPOSING an agate differ considerably in
porosity. those that are transparent, FOR
example. being less porous than opaque
LAYERS. Seine. indeed. seem 10 be alto
eCther imperyious at ordinary temperature
and pressure: and agato-wOrkers both at
Oberstein and IN India have ayaled tnem-
selves o! this popularity in applying their
staining processes. a suitable agate, alter
being thoroughly dried, is immersed in
a mixture Of honey and water or ~
olive oil. and Is kept thus for at least
three days. exposed to a moderate heat.
II is .h4n wasaed, dried. and put into
ssel containing enouEh suiDhuric acid 10
cover II, The vessel is thereafter g .'Jsed
to a gentle heat for varying number o.
hours. when the porous layers are found TO
have become much darker IN color The
reason Of this il that these layers, having
become saturated with the syrup OF oil, are
acted upon by the sulphuric acid. which
dccOmposes the sugary or oily constituent.
and forms in its N!1ce ,,,.rSit OF ccaI Uon.
II IS IN this way that banded agate Is con,
yertcd into the onyx, with its black and
white layors, used III the production OF
canoes and intaghos. Exposure to strong
sunlight was long ago found TO give
reddish tint OF gray-colored agates. and
this suggested the burning OF such stones,
so as 10 convert them into csrn6sanS, ~
Obcrstein, likely stones Tor this purpose
are first dried thoroughly, then saturated
in sulphuric acid, and afterWard exposed
in an earthenwaro crucible 10 red heat.
They are allowed to cool slowly, and are
then seen TO be OF bright red color. Not
| content with initiating the rarcr natural
varieties Of agate, such rs onyx and carne-
! Ian, German manufacturers have taken 10
| staining agates blue and eli sorts OF
colors unkuown in thcnatural stones. Ami
! ne dyes, as unnatural as they are fugitive,
| have also been lately used for agate
staining. 1t is possible that the
stones themselves may yet be artiiicially
produced - indeed, according 10 King
! r'Natural History Of Gems y a Florcntine
anatomIst long ago accomplished the feat,
although, unfortunately, the secret died
with him. He is said 10 have petrited
human vscera into real agates. "ln tue
hospital Of S. Spirito may be inspected still
by the incredulous," says King, 90 table
top made up of hearts, lungs, livers, &C,
thus agatized into one large slab-meat-
board for q banquet OF vampires !" Or
ganic remains in agate are not unknown,
for Bowerbank states that in the moss
agates Of Oberstein he has found micro
scopie organisms, and DR.. ueddie th,t he
has found mdoubted organic remains OF
considerable size in agates from Ayrshire
and other localities.
4
A Characteristic Edict Issued by tho
al.