size
of grains to that of a man's head; and sometimes in specks; it has a
conchoidal fracture; is transparent and translucent; possesses single
refraction of light; a resinous lustre in a high degree: its colors
are wine and wax yellow, greenish or yellowish white, or reddish-brown;
sometimes the colors vary in layers. It scratches gypsum, but is
attacked by carbonate of lime; its streak-powder is yellowish-white; it
has a specific gravity of l.08 to 1.10; it becomes electric by rubbing.
Before the blowpipe it burns with a yellowish and bluish green flame,
emitting at the same time a dense and agreeable smoke, and leaving a
carbonaceous residuum; heated oil softens and makes it pliable; it does
not melt as easily as other resins, requiring 517° Farenheit; it yields
by dry distillation an acid which is called succinic acid, also an
essential oil, known by the name of oil of amber, and in the retort
remains a brown mass, called the resin of amber, which is used in the
arts as amber varnish ; any essential oil, or spirits of turpentine may
be used for procuring the resin ; fat oils dissolve amber perfectly;
its elementary constituents are carbon, hydrogen, and oxygen, with some
lime, alumina, and silex.
Amber
is found either thrown up by the sea, or in the small rivers near it;
sometimes in alluvial deposits of sand or gravel in the vicinity of the
sea, or in bituminous formations, such as lignite, bituminous wood, or
jet, where crystallized minerals are at the same time found, such as
iron pyrites, &c.
Its
geological distribution is in the green-sand formation, or, according
to De la Beche, the stratified rocks, between the third and fourth
large group.
Amber
occurs in the greatest abundance on the Prussian coast, in a bed of
bituminous coal, where it is washed out or cast ashore during the
autumnal storms on the coast of
