68 QUEENSLAND GEMS 
Preripot.—A variety of olivine of a delicate green 
yellow, sometimes spoken of as the “evening emerald.” 
The antiquity of this gem is proved by the following 
passage in an old book—‘‘ Adam Sadbury, 53rd Abbot 
of Glastonbury, gave tothe Abbey, among other precious 
gifts, a gold ring with a stone called peritot, which was 
on the finger of St. Thomas the Martyr, when he fell by 
the swords of wicked men.” 
PrEARL.—Probably the pearl is the best known of all 
gems to Australians. 
For many years Queensland has produced thousand 
of pounds worth of pearls. 
The oyster fisheries of Thursday Island have been 
the chief source of supply, but pearls are found practically 
right round the coast, many good pearls having been found 
even in Moreton Bay. 
Prior to the Japanese War, pearls brought very high 
prices, running to hundreds of pounds, according to size, 
lustre and perfection of shape, good symmetrical lustrous 
whites of good orient are always in demand, and both 
black and white pearls of good color, shape and lustre 
always command very high prices. 
The most remarkable pearl the writer has seen was 
a pearl blister, exactly lke a small crayfish. This was 
described to Mr. Saville Kent, the great expert, who also 
owns a similar one, and says that it undoubtedly is an 
embalmed crustacean, having been coated by the oyster 
with a nacreous shroud. 
OpaL.—Composition ; Hydrous silica. 
Proportion of water, from 2 to 13%. 
Hardness, 5.5 to 6.5. 
Spec. Gravity, 1.9 to 2.3. 
The opal is par excellence the Queensland gem, and 
is found throughout the Western Districts of the State, 
from Kynuna to the Southern border. 
The value of the opal, so far found in Queensland, 
has in all probability 1eached the sum of a quarter of a 
million pounds. It is found in most picturesque country, 
the isolated flat topped hills weathered into the appear- 
ance of ancient fortresses recall all one’s recollection 
of the romantic history of feudal times. 
