OMINOUS AND LUMINOUS STONES 145
2,000,000 sesterces ($80,000)."4 The stone was "as large as a hazel-nut."
This
"opal of Nonius" would be the great historic opal if we had any
assurance that it was really the stone to which we now give this name.
As, however, the principal European source of supply in Hungary does
not appear to have been available in classic times to the Romans, and
as opals are not found in the places whence, according to Pliny, the opalus was
derived, we are almost forced to the conclusion that he had some other
stone in mind when he gave his eloquent description of the opalus. And
yet, in spite of all this, Pliny's words so well describe the beauties
of a fine opal that it is difficult to determine what other stone he
could have meant. For it can well be said of opals that'' There is in
them a softer fire than in the carbuncle, there is the brilliant purple
of the amethyst; there is the sea-green of the emerald—all shining
together in incredible union. Some by their refulgent splendor rival
the colors of the painters, others the flame of burning sulphur or of
fire quickened by oil."5 Possibly some brilliant varieties
of iridescent quartz— "iris" quartz, possessing an internal fracture,
displays with great brilliancy all the colors of the rainbow,
sparkling with wonderful clearness in its field of transparent
mineral—might excite the admiration of one who had never seen an opal.
Eeferring again to these quartz crystals, they are often cut so as to
form a dome of quartz and are even used as distinct jewels. The fact
that Pliny could praise the Indian imitations of the opalus in glass, and could state that this stone was more successfully imitated than any other, is an almost de-
'Plinii, "Naturalis historia," lib. xxxvii, cap. 6. "Plinii, 1. c. 10