|
BOOK VI
|
117
|
||
|
|
|||
|
gem aegyptilla has sard-red and black veins through a white stone. Paederos11 has four intermingled colors, white, purple, copper-red and golden yellow. Four distinct colors are found in eupetalos, blue, flame-red, vermillion and apple-green. Hexacontalithos and panchros have many colors.
Gems,
especially transparent gems, have many different types of flaws. Some
flaws have a color similar to smoke, clouds, shadows, etc. Some have a
solid body similar to scales, hairs, salt, dots, shavings, lead rust,
iron rust, rust and hidden ulcers. Just as the clear blue of the
heavens may be marred when a black, white or streaked cloud crosses it,
in the same fashion the beauty of a gem is marred when it contains a
smoky or shadowy flaw, is lightened by a white or cloudy area or is
disfigured by dark spots. When they are tinted with a smoky flaw they
lose their transparency and brilliancy. Transparent chrysolilhos is often smoky and the Greeks call this and the jaspis which is not transparent capnias (καπνίας). Shadows
and clouds are only found in transparent gems. Shadows have a dark
color, clouds a white or spotted color. When these flaws occur the gem
loses its true color. These flaws may be inside the gem or appear to
lie on the edge. They may darken the stone as is common with quartz and
some smaragdus or whiten it as in the case of other smaragdus. They
may spot the stone as in some quartz. In some stones the flaws may have
the same exotic color as the gem in which they occur. Scales appear to
be irregularities; hairs look like cracks. Dots of an alien color are
called "salt" because of the similarity to white mica. Points have
variable colors. "Salt" is conspicuous in quartz, points in sapphire
and certain crystals. Any of these flaws may be harder or softer than
the rest of the gem. The points which are called "drops" and "stars" we
will not regard as flaws since the golden points that sparkle in
lapis-lazuli are highly prized as are the golden "drops" that sparkle
in sandastros. Shavings do not have an alien color. Chrysolilhos, especially
that from Arabia, is sometimes filled with shavings according to Pliny.
When they are white they differ from "salt" in being much smaller. Iron
rust has an iron color; rust, red; lead, a lead color. Pliny writes
that the smaragdus from Athens frequently contains lead rust
since the lead color can be seen in the sun. They call a gem ulcerous
when it is so filthy that the interior seems to be filled with corrupt
material. If the flaws occur on the surface of a gem they can be
concealed by smearing some substance over them or they can be removed
by engraving but when they occur within the body of the gem they can
neither be concealed nor cut away. For that reason gems that contain
such objectionable flaws are neither engraved or cut further. If a
sapphire contains a point within the crystal it is valueless to the gem
cutter. The Greeks call these stones κίντρον. On the other hand beryllus is per-
• Paederos is a general term for opals and other gems showing a play of colors. The name is also given to purple amethyst.
|
|||
|
|
|||