4$ TOURMALINE. 
in large pieces perfectly clear and free from flaws, they 
are in general so soft, and have so little the brilliancy of 
other gems, that they are usually considered of inferior 
value. The most beautiful kinds are brought from 
Dauria, on the frontiers of China, from Siberia, and 
from Brazil. They are also found in Saxony and the 
South of France, and are very common at Baltimore, in 
North America. Specimens of aqua marine have been 
obtained from the upper parts of Aberdeenshire, Scot- 
land, where they sometimes occur in alluvial soil, along 
with rock crystal and topaz. These stones have also 
been found, embedded in granite, near Lough Bray, 
and Cronebane, in the County of Wicklow, Ireland; 
and also in mountain rock, in some parts of Devonshire. 
They are cut by means of emery (58), and polished 
with tripoli (119). The darkest green specimens are 
set -upon a somewhat steel-coloured foil ; and the pale 
ones are either placed, like the diamond, on a black 
ground, or upon a silvery foil. The aqua marine is 
usually made into necklaces ; but it is likewise employed 
for brooches, and not ^infrequently for steel stones and 
intaglios. The larger ones are in much esteem among 
the Turks for the handles of stilettos. 
6.9. The TOURMALINE is a stone belonging to the same 
family as the emerald, and generally of a smoky blackish co- 
lour : sometimes, however, it is green, red, blue, or brown,; 
and, when not very thick, it is transparent. 
It is occasionally found in shapeless masses, but more fre- 
quently crystallized in three, six, or nine-sided prisms, va- 
riously truncated or terminated ; and 'its weight is somewhat 
more than three times that r cf water. 
This stone was first made known in Europe, about 
the beginning of the last century, by the Dutch mer- 
chants, who brought it from the island of Ceylon, where 
it is principally found. When strongly heated it be- 
comes electric ; one of the summits of the crystal ne- 
gatively, and the other positively. An early writer, by 
whom it is mentioned, says, that " it has the property 
