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124
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DE NATURA FOSSILIUΜ
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In conclusion we may say that the white or colorless gems are quartz, pangonius, diamond, androdamas, opal and asterios. Regarding the form and features that distinguish one from the other, quartz, pangonius and androdamas are always angular, diamond, sometimes. Opal and asterios are not angular but usually rounded. Pangonius is distinguished from the other angular gems by the large number of angles. The others are either hexagonal or cubic. Androdamas being
cubic is easily distinguished from quartz and diamond, in fact from all
angular white stones because all the others terminate in a point if
they have their natural form. Diamond can be distinguished from quartz
by hardness. Opal is distinguished from asterios by inclining
the gem. The former will change color while the latter will reflect a
round inner light. Diamond is the most valuable of all these gems. A
king of the Turks bought one twenty-three years ago for nine hundred
and fifty pieces of gold. Next in value is the opal and third, the sangenis. After these comes asterios and then pangonius because
of its rarity. However, quartz, if it is in crystals large enough that
a vase can be cut from them, commands a high price for Pliny writes
that a wine
ladle was purchased from a not too wealthy lady, Η---------s, for eight
hundred
and fifty pieces of gold. I have said enough concerning the white and
multicolored gems and will not take up the green gems.12
The first green gem to come to our mind is smaragdus. The Greeks have given it this name because of its brilliancy. According to Pliny it is called limoniates (λβίμωριάτητ), a
moist green pasture). It is found in Asiatic Scythia; Bactria; Media;
Perseis; the gold mines of Arabia; in the mountains and rocky wastes
of Egypt near Keft, a town of Thebes; in the copper mines of
Carthaginia that are on Mt. Smaragdites; in Sicily; on Mt. Tagyetus,
Laconia; near Kastri, a town of Greece; in the silver mines of Attica;
at a place called Thoricus; and in the copper mines of Cyprus. The
color of the finest smaragdus is a dense bright green and the
body of the gem is not only brilliant but as transparent as water. Gems
of this quality are found in Scythia, Bactris, Egypt and Ethiopia.
Those from Kastri are an oily-green as are the finest from Cyprus
which, if examined carefully, are seen to have the translucency of the
sea. While this gem can scarcely be said to sparkle nevertheless it
does have the apparent property of tinting the air around it,
especially when it is lighted by the brilliancy of the sun or a lamp or
when a shadow darkens it. For that reason, when
12 There is some confusion in the use of these various names. Quartz and pangonius are
the same mineral, the latter being a crystal with twelve prismatic
faces. There is a certain confusion in the identification of quartz and
diamond since the hexagonal crystal terminating in a point is
obviously quartz. Androdamas which is described as cubic may be diamond since this is one of the forms of this mineral. It is impossible to identify siderites but
it must be some mineral other than diamond. Since it was believed that
the hardness of diamond could be materially reduced by soaking the
stone in goat's blood it was easy to consider any transparent,
colorless stone as a treated diamond. Asteriated gems have long been a
source of wonder and it is strange that Agricola should apply this name
and its variations to the gem now known as moonstone.
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