XXXVI.
HEMATITE.
The hematite, or blood stone, thus called from the Greek αΐμα, blood, to
indicate its tint, is a substance which ought not to be placed amongst
gems. It is a sesquioxide of iron, as perfect as the oxide of copper
which the malachite yields.
It
is used for making those tools called burnishers, so necessary to
goldsmiths, to setters of gems, gilders and polishers of precious
stones.
We
bring it to notice here, merely to remark that this mineral was the
substance used in making those very ancient cylindrical seals, engraved
all round, which were for the most part found in the ruins of Babylon
and Nineveh, and known by the name of Assyrian cylinders, and which
were used for making the impression of their engravings, in the same
manner as printers use cylinders to ink type. These seals, in the
opinion of antiquarians, are the most ancient oriental memorials of
stone engraving.
XXXVII.
EPIDOTE.
Aluminous silicate
in rhomboidal prismatic crystals, transparent and striped ; of an olive
green, more or less dark ; it takes its name from the Greek word ίπιdίdωμι, which signifies to add to, because traces are perceived of the successive increase of its volume by depositions of new strata on the outside.
