Radiated Oxide of Iron, or Hæmatites
- Class 3. Metals.
- Order 1. Homogeneous.
- Gen. 7. Iron.
- Spec. 3. Oxide of Iron.
- Div. 2. Imitative.
- Red Hæmatite. Kirw. v. 2. 168.
- Roter Glass-kopf. Emmerl. v. 2. 313.
- Hematite. Haüy, v. 4. 105. De Born, v. 2. 287, XI, V. c. b. 1.
The Hæmatite Iron ores are found near Silverstein in Lancashire in great variety and abundance. The upper specimen is somewhat singular, from the separating and divaricating radii. The lower figure shows more of the usual structure of these ores, which often form large roundish or irregular nodules, sometimes kidney-shaped, botroidal, &c. the masses radiating from one or more centres, 6 inches or more inlength, and casing or coating one over another. They are mostly of a brick red colour, easily staining the fingers, particularly the powdery parts:—the harder parts also stain the fingers much, and by a little rubbing give a black tinge with a bright lustre not unlike black lead. Those parts which have lost the red appearance, and approach the metallic or iron lustre, do not readily stain the fingers. On being ground these give a deep red colour; whence this ore has been called Blood Stone. Sometimes the harder black sort with this property is cut into burnishers for gilders.
These ores are said to contain from 40 to 80 per cent. of iron. The harder kind is sometimes a little magnetic, if reduced to powder, particularly if heated on charcoal; which deprives it of a certain quantity of oxygen. “Fracture coarse or fine fibrous, parallel or divering, earthy.” Hardness, from such as may be easily scraped with a knife to such as will strike fire with steel. Spec. Grav. from 4 to 5, Kirwan.
“This ore contains, besides some manganese, a large proportion of argill, which renders iron it affords red-short, that is, brittle when red hot.” Kirwan.