Crystallized Oxide of Iron Enlarge
Feb.y 1. 1804. Publiſhed by Ja.s Sowerby. London.
British Mineralogy
Ferrum oxygenizatum, var. crystallizatum

Crystallized Oxide of Iron

  • Class 3. Metals.
  • Order 1. Homogeneous.
  • Gen. 7. Iron.
  • Spec. 3. Oxide of Iron.
  • Div. 1. Crystallized.
  • Gen. Char. Colour grey. Harder than most other metals. Attractible by the magnet. Spec. Grav. 7.2–7.84. Kirw. Capable of combustion by collision. Bab. Soluble in all the acids; precipitable from its solutions, the precipitate being of a blue colour, by prussiate of potash.
  • Spec. Char. In combination with above 24 per cent. of oxygen.
  • Syn.
    • Specular iron ore. Kirw. v. 2. 162.
    • Fer oligiste. Haüy, v. 4. 38.

The peculiar form of this minute crystallization I could not pass over, especially as it may be a very proper one in arranging the varieties of the species to which it belongs. The sort of iron ores from Lancashire, on which these crystals are sometimes found, is not uncommon: there are also minute quartz crystals, frequently very transparent, attached to this ore; which on the dark ground deceive us with the idea of crystallized iron ore: however, with the help of a lens, it may often be discovered whether we are right or not, by the form of the crystals. The latter, although a seeming modification of carbonate of lime, appear to be slightly magnetic. It is a very curious circumstance that this should so generally resemble, in the form of its crystal, the carbonates of lime, this being like a flattened æquiaxe with various modifications. Romé de Lisle’s, p. 4. f. 62. is the nearest resembling it, wanting only the 6 alternating narrow faces. The fracture is intermediate between glassy and splintery, and when fresh broken it shows an iron or steel-like lustre. The outsides of the crystals are of a darker iron or steel-grey with much gloss or polish; the edges of some resemble blued steel, and sometimes reflect other colours. They stand edgeways on the matrix; which makes this hue more conspicuous, and adds much to the beauty of the specimen, especially when magnified.

We presume this is the same as the beautiful iron ore from Elba, now first noticed in England.

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