Summary

William Phillips Transactions of the Geological Society (1811)

The fracture of the crystals, particularly of the more translucent ones, is very smooth and inclines to conchoidal; but is frequently uneven, and inclining to shattery, in those of a darker hue. I have met with some octohedrons that admitted a fracture in the direction of their faces, but have not found any of a cubical form in which a division parallel to the circumscribing planes was practicable.
The form of the primitive crystal, according to Haüy, is the regular octahedron (fig. 1.)
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William Phillips Transactions of the Geological Society (1811)

That beautiful mineral, the cubic arseniate of iron, was also found at and near the junction of the Great Gossan and Muttrell Lodes; but occurred in greatest quantity in the latter, thirty fathoms west of the junction, about the adit level; being forty-six fathoms higher, though perhaps not immediately above the part in which the first discovery of the red oxyd took place.
Source: Wikisource

William Phillips Transactions of the Geological Society (1811)

The crystals of this substance are mostly well defined, but do not in general exceed a line in length. The largest in my collection is nearly half an inch; I have seen others somewhat larger. They are however frequently so small, as to appear to the naked eye a mere point, but by the assistance of the lens, the perfection of their geometrical forms may easily be discovered: a perfection rarely observable in the larger crystals. They are generally of a considerable external lustre, occasionally approaching to metallic; and are sometimes, though rarely, iridescent on the surface.
Source: Wikisource

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