|
ONYX.
|
269
|
||
|
|
|||
|
women
for paint (pearl-powder ?), grind them fine ; then steep the powder in
lemon-juice, frequently passed through a filter, so that the juice be
three or four fingers deep over it. Let the mixture stand thus, well
covered over, for ten days in a warm place ; then pour off the juice ;
wash the residuum in water ; grind it up in a porphyry mortar with
white of egg well beaten up beforehand ; then cast the cement in moulds
of the required design, made in wax. Next polish with great nicety the
rough back of these casts, so that they may be applied skilfully and
neatly upon a black ground, that the deception may not be readily
detected. In rubbing down the shells, other colours can be added in
fine powder, so that the Sardonyx may be imitated in this way as well
as the other precious stones."
Georgius
Agricola (d. 1485) has a passage interesting as showing how rapidly
the newly-revived art of gem-engraving had found its way into Germany
:—" Nowadays, in the opaque white crust of the German Onyx
(Agathe-onyx), engravers cut the coats-of-arms, the pride of noblemen,
because this stone has veins more translucent than any other of the
same kind, and moreover is harder than rock-crystal. They also paint
the hack of these coats-of-arms with the proper tinctures required by the armorial bearings."
The
Onyx, strange to say, considering its high repute in ancient times,
bore a most unfavourable character in the Middle Ages, Marbodus
asserting that its wearer was exposed to the assaults of demons and of
ugly visions by night, besides being plagued with quarrels and lawsuits
by day. The sole remedy was to wear a Sard as well, which would
completely neutralise the mischievous influence of the Onyx.
|
|||
|
|
|||
|
|
|||
|
|
|||