country
as white topaz, and command a fair price. Well-cut seal-stones are sold
at from five to twenty dollars. Those of the brilliant-cut are sold at
from fifty cents to a dollar a piece. The largest rock crystal is said
to be in the collection of M. Rafaelli, artist, at Rome,—and a large
candelabra of iridescent quartz, is in the Vatican. The proprietors
of the American Museum of this city, can boast of having one of the
largest specimens of rock crystal from Brazil. It weighs two hundred
and twelve pounds, is two feet and a half high, and one foot in
diameter, and is a perfect six-sided prism.
Two
large crystals of quartz, attached by one of the-vertical faces, the
crystals being each two and a half feet high by eight inches in
diameter, were exhibited by the Duke of Devonshire, at the London
Exhibition, in 1851. The pyramidal summits of these crystals, which
rise nearly a foot above the prism, are completely transparent, but the
prisms are cloudy. These magnificent crystals were obtained from the
Alps, having been discovered during the formation of the road over the
Simplon, in a cutting made through the old rocks. I saw a most
magnificent chandelier of rock crystal in the Tuileries, which is said
to have cost one hundred thousand francs. The clearest rock crystal
comes from the island of Madagascar, in blocks weighing from fifty to
one hundred pounds. In Switzerland, and the province of Auvergne, in
France, very fine specimens may be had. The Bristol, Buxton, Cornish,
and Irish diamonds, which are all pyramidal crystals of quartz, are
known all over the world.
A
specimen of rock crystal in the Museum of Natural History, at Paris,
measures three feet in diameter, weighs nearly eight hundred pounds,
and was found at Fischbach, in France.
Rock crystal may be easily distinguished from white
