406 * 
OPAL. 
its substance is penetrated by the most agreeable 
colours, which give it a very delicate appearance. 
Pliny celebrates the opal as possessing all the fire 
of the carbuncle, the purple of the amethyst, the 
green of the emerald, sometimes separated, some- 
times mixed in the most admirable manner. To 
these colours may be added the blue and the 
orange, which frequently join them as auxiliaries, 
and together form a stone of the most beautiful 
aspect. 
An opal of a considerable size, in all the parts of 
which the colours are not only brilliant, but pro- 
perly varied, is so rare a production that it can 
hardly be estimated at any price. Pliny mentions 
one which belonged to the senator Nonius, who ra- 
ther chose to suffer banishment than part with it to 
Anthony. This stone was in Rome at that time 
valued at 2000 sestertii. 
Cronstedt describes an opal which appears olive- 
coloured by reflection, and seems to be opaque ; but 
when held against the light is found transparent 
and of a fine ruby colour. This stone was dis- 
covered among the ruins of Alexandria. It is about 
the size of a hazle-nut, and was bought for a trifle 
of a French drogoman, and presented to the French 
consul Lironcourt, who afterwards offered it for sale 
in several places for the sum of 40,000 rix-dollars. 
The opal is found in little masses, in veins scat- 
tered among rocks which appear to be partly de- 
composed, and about the nature of which naturalists 
seem to be divided ; some supposing them to be 
