Subsulphate of Iron

The upper specimen of this substance is from the East Indies, and is here figured by favour of the Count de Bournon, to whom it belongs, as does also the lower specimen, which was part of the contents of a small box found in Ferber’s collection. Ferber himself formerly gave the Count a specimen, but it shared the same unhappy fate as the rest of the Count’s collection in France. The first is upon an argillaceous matrix of a grey colour. The upper side is an oblique view, and shows a somewhat irregular incrustation of the substance, which is very brittle and tender, of a rezinous fracture, and the colour approaches that of rezin in the interior; the upper surface, or crust, which is mostly broken off, is of a warm deep brownish red, or scorched hue, with a very delicate greyish bloom, if I may so call it, in some of the fissures.

In consequence of its extreme brittleness, it crumbles to pieces with a very slight touch. It was examined by the accurate Dr. Woolaston, who finds it to agree with Ferber’s specimen.

The lower specimen inclines to ochraceous in some parts, and is of a rich scorched dark brownish red colour in others; it has a large conchoidal fracture, and is semi-transparent, showing very rich glowing reflections. This is a part of Ferber’s specimen from the mine of Kust Bescheerung, near Freyberg. Spec. Grav. 2.144.

Haüy observes, that upon exposure to the flame of a candle it melts and becomes magnetic.