66 THE CURIOUS LORE OP PRECIOUS STONES
The
"Serpent Isle," in the Red Sea, was stated by Agatharcides to be the
source whence came the topaz (chrysolite) ; here, by the mandate of the
Egyptian kings, the inhabitants collected specimens of this stone and
delivered them to the gem-cutters for polishing.30 These
simple details are elaborated by Diodorus Siculus into the legend that
the island was guarded by jealous watchers who had orders to put to
death any unauthorized persons who approached it. Even those who had
the right to seek the gem could not see the chrysolite in daytime; only
after nightfall was it revealed by its radiance; the seekers then
marked well the spot and were able to find the stone on the following
day.31
From
this Egyptian source, and possibly from others exploited by the
Egyptians, have come the finest chrysolites (peridots, or olivines),
the most magnificent examples of this gem. These found their way into
the cathedral treasures of Europe, evidently by loot or trade at the
period of the Crusades, and are generally called emeralds. Those most
notable are in the Treasury of the Three Magi, in the great "Dom," or
Cathedral at Cologne. Some of these gems are nearly two inches long.
In
our own land beautiful specimens can be seen in the Morgan collection
at the American Museum of Natural History and in the Higinbotham Hall
in the Field Museum of Natural History, Chicago, Illinois.
Pliny quotes from Juba the tradition that the topaz (chrysolite) derived its name from the Island of To-
"
Agatharcides, " De Mare Erythraeo," §2. The topaz of the ancients was
unquestionably the gem commonly called chrysolite at present (olivine,
peridot).
" Diodorus Siculus, lib. iii, cap. 38.
