IRON. 
383 
Under these circunstances, the specimen almost always contains a small proportion of nickel 
or chromium. In a few cases, however, native iron of undoubted terrestrial origin has been 
found. Such are the varieties from Canaan, Connecticut, and from Guilford in North Caro¬ 
lina ; the latter of which consists of a single octahedral crystal, now in the Cabinet of Yale 
College, weighing seven ounces, and which is said to have been detached from a mass weigh¬ 
ing twenty-eight pounds.* 
LOCALITIES. 
Otsego County. In the cabinet of the Albany Institute, there is a specimen labelled 
“ Native Iron from Burlington,” in this county. It was received from Prof. J. Hadley, but I 
know nothing further of its history. It is malleable, and has a blackish coating. 
Yates County. Mr. T. G. Clemson has described a specimen of what he called native 
iron, found near Penn-Yan. It was represented as being from a larger mass found in a sand¬ 
stone rock. It acted on the needle, was free from oxides, and contained a minute portion of 
carbon, but neither nickel nor cobalt could be detected in it.f 
MAGNETIC IRON ORE. 
[In allusion to its magnetic properties.] 
Fer Oxidule. Haiiy. — Magnetic Oxide of Iron. Cleaveland. — Octahedral Iron Ore, Black or Magnetic Iron 
Ore. Jameson. — Magnetic Iron Ore, Thomson and Dana. — Octaedrisches Eisen-Erz. Mohs. — Oxidulated 
Iron. Phillips. — Aimant. Eeudant. — Magnetic Iron. Shepard. 
Fig- 437 - Description. Colour usually iron-black, but sometimes bluish 
or steel-grey. Streak always nearly or quite black. It occurs re¬ 
gularly crystallized ; also in grains, massive and disseminated. The 
primary form is a regular octahedron, Fig. 437. Cleavage parallel 
with the primary. Fracture uneven or conchoidal. Lustre metallic. 
Opaque. Brittle. Hardness from 5.5 to 6.5. Specific gravity 
from 4.74 to 5.20. It is attracted by the magnet, and sometimes 
exhibits polarity. Infusible by the blowpipe alone, but becomes 
brown, and loses its magnetism. With borax, in the oxidizing 
flame it fuses into a dull red glass, which becomes clear on cooling, 
and often assumes a yellow tint; in the reducing flame, it becomes bottle-green. Insoluble 
in nitric acid, but usually soluble in hot concentrated muriatic acid. Sometimes, however, 
it is necessary to calcine the ore with carbonate of potash or soda, before its solution can be 
effected. The black colour of its powder, and its strong action upon the magnet, will usually 
serve to distinguish this species from the specular iron ore which it often resembles. 
Shepard. Treatise on Mineralogy. II. 70. 
t Transactions of the Geological Society of Pennsylvania. I. 358. 
