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MINERAL RESOURCES.
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extreme hardness was subsequently verified by the writer, who carefully examined the type specimen.
Dr.
Oliver W. Huntington has contributed much valuable information in
regard' to this meteoric iron. The results were first announced in Science, on
April 8, 1892, and were read in detail before the American Academy of
Arts and Sciences on May 11, 1892, and afterwards published in the
Proceedings, new series, Vol. xxii, p. 252, and in Science of July 8, 1892.
He
placed 100 grams of iron in a perforated platinum cone suspended in a
platinum bowl filled with acid, the cone being made the positive pole
and the dish the negative pole of a Bunsen cell. The iron slowly
dissolved, leaving on the cone a large amount of black slime. This was
carefully collected and digested over a steam bath for many hours first
with aqua regia, and afterwards with strong hydrofluoric acid. Most of
the residue disappeared, but there remained a small amount of white
grains which resisted the acids, and, when carefully separated by hand,
resembled fine beach sand. Under the microscope they were found to be
transparent and of brilliant luster. One of the grains was then mounted
upon a point of metallic lead and drawn across a watch crystal, when it
gave the familiar singing noise characteristic of a glass-cutter's tool
and with the same result, namely, cutting the glass completely through.
It deeply cut glass, topaz, and a polished sapphire.
Subsequently
M. C. Friedel says, in the Bulletin de la Societe Fran-caise de
Mineralogie (No. 9, p. 258, December, 1892), that he took a fragment of
the Canyon Diablo meteorite, weighing 34 grams, with the characteristic
Widmannstattian figures, and treated it with hydrochloric acid. He
digested the residue in aqua regia and obtained a black powder. After
various treatments he thus separated about 0.35 gram of a powder, which
he presented to the Academy. No grains were found measuring more than
0-5 mm., the powder being fine and impalpable, capable of scratching
corundum, and sinking in a solution of iodide of methyl having a
density of 3-3. He also burned some of the black residue, and as a
product obtained CO2.
At
the meeting above referred to of the Academy of Arts and Sciences Dr.
Huntington showed to the members, under a microscope, the slightly
yellow transparent grains he had obtained, and called attention to
their adamantine luster. Not enough of the clear material was obtained
at the time for a chemical test, and, on account of the association of
the diamond grains with amorphous carbon, such a test would not have
been conclusive without a perfect mechanical separation. The writer
suggested that if enough of the clear grains could be obtained to
polish a diamond it would be a conclusive test.
For
this purpose about 200 pounds of the meteoric iron was carefully
examined, and specimens which appeared to contain diamonds were
dissolved. The method used will be published by Dr. Huntington later.
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