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HEMATITE
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Hematite
is an oxide of iron occurring in nature which takes on a variety of
forms and shades, but is used in jewelry only when compact and of an
iron-black color. In this form it is used especially for intaglios,
but also for carving into ornaments of various sorts. Its hardness is
6, and specific gravity 4.9-5.3. Its composition is, iron 70 per cent,
and oxygen 30 per cent. While in a mass it is invariably opaque, and
often black in color; in a thin splinter it may be seen to be slightly
translucent and red. This red color always characterizes the powder or
streak of hematite, and is one of the surest means of identifying the
mineral. As the color resembles that of blood, the Greeks believed the
mineral to be concreted blood, and the name hematite is from their word
for that substance. Under the name of bloodstone it was long believed
to be a curative of hemorrhages, and Robert Boyle, the eminent
physicist, writing as late as 1672, gravely relates a cure of a case of
nasal hemorrhage of long standing through wearing a bloodstone about
the size of a hen's egg about the neck.
Powdered hematite forms the rouge of commerce used so extensively for polishing.
Hematite
was used in the carved form by the ancients as well as the moderns, a
number of cut pieces having been found in the ruins of Babylon.
Intaglios of it have also come down to us from the Romans. Large
polished surfaces of hematite make excellent mirrors, and frequent use
was made of it for this purpose in earlier times. Hematite is so
abundant over the earth's surface that it has little intrinsic value
except as an ore of iron. That used in jewelry comes largely from
northern Spain. Hematite of a similar character is obtained in the
Island of Elba, Cumberland, England, and in the Lake Superior region of
our own country. Besides its use for seals, it is employed to make
imitation black pearls. Certain fibrous occurrences of hematite when
cut in rounded forms give a starlike appearance similar to that
exhibited by star sapphires.
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188
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