Hematite was once largely used to engrave upon, many of the ancient
intaglios being on this mineral. It is now cut to simulate black
pearls, and is also used in the cheaper jewelry, both engraved and cut
cabochon.
Hematite has the hardness of 5.5 to 6.5, and specific gravity, 4.2
to 5.3; it is opaque, and shows a red streak when scratched. It is
composed of:
Iron 70
Oxygen 30
The colors of hematite are dark-steel gray to iron-black, and sometimes
brownish- to blood-red. The lustre is highly metallic, with slight
iridescence.
The island of Elba, France, Switzerland, Italy, Norway, Sweden,
Bohemia, England, Brazil, Chili, Canada, Spain, and the United States
are places where hematite is found. The Germans call this mineral
“blood-stone,” and it is also known as specular iron ore and iron
glance.