XLI.
GAGAT, OR GREEK JET.
This substance,
-which is a sort of compact lignite of very fine texture, and a
beautiful black, presents a succession of folds, and is of easy
cleavage.
Its specific gravity is 1*3, but some of it remains floating.
It catches fire quickly, emitting an unpleasant smell. When rubbed it acquires magnetic power, and therefore was also called black amber.
Although
not hard, the gagat has sufficient consistency to allow of its being
worked at the lathe, cut and polished. It can be repolished, being
rubbed with walnut oil.
It
is found in mines of fossil carbon, in round pebbles of every size.
Very often, impressions of fish are found in it, as in slate. ,
In
Prussia it abounds in the caves of amber, to which substance it often
serves as an envelope, and to which it really bears a great resemblance.
At the present day it is used for making feminine ornaments to be worn in mourning.
In
ancient times it was also used in making ornaments for women, and of
this we have full proof in the beautiful articles found in 1841 at
Cologne within two mortuary chests, deposited under the principal
entrance of the church of St. Gideon; they consisted of buckles,
armlets, rings, necklets, hair pins, and
