It is, of course, a self-evident fact that the magnetic iron ore, which is a form of peroxide, commonly known as magnetite, or lodestone, has the power of attracting a magnet when swinging free, or of being attracted by a magnet, to account for which many plausible reasons have been advanced.
"The Chemistry, Properties and Tests of Precious Stones"
John Mastin
magnetite, Titanoferrite, and Iron-pyrites also occur as normal constituents of various igneous rocks, although in very small amount, as also Apatite, or phosphate of lime.
"The Student's Elements of Geology"
Sir Charles Lyell
One of the most interesting and striking investigations made by Edison in this connection is worthy of note, and may be related in his own words: "I felt certain that there must be large bodies of magnetite in the East, which if crushed and concentrated would satisfy the wants of the Eastern furnaces for steel-making.
"Edison, His Life and Inventions"
Frank Lewis Dyer and Thomas Commerford Martin