|
BOOK VI
|
123
|
||
|
|
|||
|
Egypt,
Arabia, Pontus, Galatia, Thasos and Cyprus. The Indian gem is the best,
then the Egyptian and last the Arabian. The Pontian stone is of little
value because it lacks brilliancy. The Galatian, Thasian and Cyprian
stones are dull and of little value.
A third variety is called eristalis. This has a red color when inclined. Ophesus calls this variety opalius, unless
I have made a mistake, and writes that it has the delicate coloring of
a young boy, i.e., white tinted with red. There are many other
varieties of paederos since by merely inclining the gem one
can add to it's white luster either the golden yellow of wine, the blue
of the heliotrope, the pale color of quartz which has less luster or a
kind of blackness that darkens the gem. Pliny classes some of these as
defective opals, hence it can be understood why one writer calls all
gems of this genus opali, another paederotae. Species of paederos are also found in the localities mentioned above. The flaws found in these gems are usually scales, "salt" or hairs.
Another
gem also forms from the colorless quartz essence that has a white
internal gleam which resembles that of a star. For this reason it has
been called asteria, asterios, astroites, astrios, astrobolos and solis gemma by different writers, names which Pliny has collected from almost all writers. Pliny himself prefers the names asteria, because the gem reflects the dazzling white rays of the sun, and astrios because
it receives and reflects the brightness of the stars. But each of
these properties is common to all of the others. We know this to be one
and not several gems because the names are almost identical; the places
they occur are the same, for example, Carmania and India; they are the
same white color; they have the same white brightness; when they are
rounded one writer says they resemble the pupil of the eye, another the
full moon, another the round disk of the sun. Pliny writes that when
inclined the gem reflects the light from the interior as though it were
moving from one point to another and it is not unlike the carbunculus in this respect. The gems that reflect a white light are the best. Those that reflect a blue light are inferior and are called ceraunia because
of the belief that the place where they may have been found had been
struck by lightning although this has been proven to be false. The gems
reflecting a light similar to that of a lamp are the least valuable.
The beauty and value of these gems is judged according to the place
where they are found and on this basis the gems from Car-mania are
regarded as the finest and less subject to flaws. Second quality gems
come from India and the third from Pallene on the shores of the
Thracian peninsula. This gem is quite hard and for that reason
difficult to engrave. When polished it is usually given the form of a
hemisphere. Sudines writes that astrobolos resembles the eye of a fish.11
11 Agricola is without doubt here describing various adularescent gems, chalcedony moonstone, feldspar moonstone, girasol opal and sapphire, and he has probably included aventurine feldspar and labradorite. Some of these names embrace other minerals. Asteria may have embraced all the asteriated gems. Astroites is coral and is probably included here because of the radiating structure of certain species.
|
|||
|
|
|||