Allophane Enlarge
[Undated]
Exotic Mineralogy
CXI
Argilla allphanes

Allophane

  • Syn. Allophan. Strömeyer annalen der physik. J. 1816. St. 10. Thomson’s Annals of Phil. ix. 244.

The specimens of this new mineral were communicated by Professor Strömeyer; they were found at Gräfenthal, near Saalfeld.

Allophane; so called from its deceptive aspect, arising from its situation and colour, whence it might be taken for an ore of Copper, and not an earthy mineral: occurs in a mammillated form, lining, or filling thehollowsof a vesicular ochraceous Iron stone, and is accompanied by blue and green Carbonate of Copper. Its fracture is perfectly conchoidal, it is soft and very brittle; the external surface is dull: the lustre of the fractured parts is vitreous: it is transparent. The specific gravity varies from 1.852 to 1.889.

Strömeyer has given the following analysis, from which it appears to be an Hydrate of Argilla and Silex, coloured by Carbonate of Copper.

Argilla 32.202
Silica 21.922
Lime 0.730
Sulphate of Lime 0.517
Carbonate of Copper 3.058
Hyrdrate of Iron 0.270
Water 41.301
100.000
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