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BOOK X
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209
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There
are two bismuth minerals among the mixed substances, one black, the
other almost gray. It is customary to include here the lead minerals
that are yellow, light red, and black as well as the iron minerals that
are black or red.
I shall now consider certain species of the fourth genus that have been given specific names, for example, galena, pyrite, cadmia, andstibnite. Plumbago (galena) takes its name from plumbum. The Latins have taken this word from the Greek word μολίβδαινα. Each has taken the name from lead, which it contains and which the Greeks call μόλφδον. As a rule, it also resembles lead in color. Pliny calls this mineral galena. This
is either a Spanish word or if from some other tongue its origin is
unknown I am sure. Following the Greeks certain writers divide this
mixed compound that Pliny calls galena into three varieties. The first variety Dios-corides has called μολιβδοβιδή? λίθος and we correctly call it a stone that has the appearance of lead or, as we say, plumbarius; the second Dioscorides calls μολί/ϊδιτίδια άμμος and we call it plumbaria arena. The third Dioscorides calls μολίβδαινας and we call it plumbago. The
latter was mined near Sebastia which is not far from Corycos, Cilicia.
Galen did not mention the stone that has the appearance of a species of
lead as a separate variety nor did he mention plumbaria arena. However, when he discusses the nature and properties of plumbago he writes that he himself had seen plumbago, lying along the road between Pergamus and the smelter, having the appearance of a species of stone the same as does the cadmia found in the mountains and rivers of Cyprus. Stones and sand are often coated with a color similar to lead.
Plumbago is golden yellow in color.17
Both the stone and the sand have a brilliant luster and contain lead.
The stone and sand are sometimes coated with an alien color, black,
blue or brown but within they have their true color that is readily
apparent when they are broken with a hammer. As the stone contains more
silver it approaches the color of argentite. A certain plumbarius lapis has
a luster very similar to stibnite but they can be distinguished easily
since stibnite is soft and fragile while the former is hard and
difficult to crush. The form varies just as does that of argentite.
Sometimes only lead is obtained from this variety as well as from the
others, for example, that from Villachum, Noricum, and most of the
British ores which are silver-free. Sometimes both lead and silver are
obtained and those ores are common. The ore from Freiberg, Misena,
formerly contained two pounds of silver per hundred pounds of mineral.
Some mineral contains only an ounce of silver per hundred pounds as
that from the mines of Poland and Suebia. The mineral from Chemnitz in
the Carpathian Mountains contains only one-half ounce per hundred
pounds. As to the lead content of the mineral, they obtain fifty pounds
from one hundred pounds of galena from Pleistadt,
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17 Plumbago flava is wulfenite, a lead molybdate.
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