282 NATURAL EISTOBT OF PRECIOUS STONES, &c.
of
which the one half was Emerald, the other half Jasper,* as being not
completely transformed as yet by the action of the fluid. There is a
peculiar method of working up this stone so as to give it lustre, for
in the native state it has no brilliancy."
It
is plain from the above that his Cyprian gem was merely the transparent
Chrysocolla, still called the " Copper Emerald ;" the remark that it
could be used in soldering gold decides the question. But that kind
qualified as "rare and small in size" was as indubitably the genuine
one, for the Egyptian mine of the true Emerald had been worked ages
before his times.
Pliny
(xxxvii. 16) gives a long list of the various species of the Smaragdus,
to the number of twelve, and of the localities furnishing each kind.
The greatest part ot these, the description of which he quotes from earlier writers,
are evidently nothing more than calcedonies tinged green, or else
carbonates of copper of different shades : a distinction must be made
where he speaks from his own observation. First in the list he places
the Scythian, " the best of all on account of its depth of colour and
freedom from flaws (nullis major austeritas aut minus vitii), and as
superior to other Emeralds as the Emerald itself to other gems." Their
extreme hardness prevented their being engraved. All these
characters, but especially the last, indicate this gem as the Green
Ruby, a very rare variety of the Precious Corundum, and which indeed
ought rather
