stone
render it little adapted for cutting. Many attempts were made to
engrave it at the beginning of this century, and many ornaments were
made of it, but they did not result in good works of art.
LXI.
MARQUISITE.
Sulphuret of
iron, in mineralogy and in jewellery, takes this name, which is to me
of unknown etymology, unless we allow it to come from the French word marquis, which would in that case be the base of its name in that language, marquisite.
As, at the time when firearms were invented, it was used instead of flint, it therefore took the name of pirite, from the Greek πυρ, fire.
The
marquisite is found in large pieces, in the shape of a cube and the
forms derived from it. It has a vitreous and very bright cleavage. It
is found pure in various forms, including the hemispheric and
dode-cahedric. Its specific weight varies from 3'900 to 4.904. When cut
in facets like the rose diamond it is very bright. But all the
marquisites in commerce are generally small, not exceeding in size a
gem of 2 carats.
There
are many varieties of marquisite, some tending to bronze, others to
grey, or steel colour. When struck by the steel, it emits numerous
sparks which exhale a sulphurous smell.
Metallic, arsenical, and sulphurous particles abound,
L
