Honduras specimen, weighing six hundred and two carats,
valued at twenty-five thousand dollars, together with verybeautiful green and purple varieties from Queensland, and
fire-opals from Mexico, attracted the notice of visitors to the
Centennial at Philadelphia, and the collection at the Exposition
in New Orleans embraced a great variety, including jasperopal, cachelong, hyalite, black opal from Bohemia, semi-opal of
a snuff-brown color, precious opal, wax-opal of dark variegated
tints, from Hungary, a variety from Tripoli, resembling a reddish sandstone in appearance, black wood-opal from California,
brown wood-opal from New Zealand, a kind named geyserite,
from Yellowstone Park, yellowish, light brown, and white from
Colorado, and opals from the Island of Elba. It is related by
Mr. Hamlin that one of the most beautiful jewels seen in this
country is a necklace made of opals obtained from Honduras,
cut and mounted in gold, — with diamonds. They were
secured by Dr. J. Le Conte who has given some important
facts about the mines of this region, in his report of the InterOcean Railroad Survey.
The Pearl. — This precious substance has been considered
from time immemorial one of the most beautiful and valuable
productions of earth, and has been sought, at almost infinite
labor and expense, as one of the loveliest gems that ever
graced a coronet.
Pearls, in the strictest sense, cannot be called precious
itones, since they have their origin in the animal kingdom ;
they are thought to be concretions of carbonate of lime and
organic matter found in certain animal species, deposited in
thin films which overlie one another, thus causing the beautiful
iridescence characteristic of these organic productions. They
are found both in marine and fresh-water mollusks, usually
the pearl-oyster and the Unio, a fresh-water mussel, though
