Sulphuret of Iron—Iron Pyrites

This is a modification depending on the same laws of aggregation as the last; but the notches are filled up by a continuation of the striated faces; the crystals are much compressed, and often very thin, having the appearance of hexangular plates, three sides of which stick deep in the gangue: they however terminate more or less solid in two or three angles only, against each other, or in the more massy part of the Pyrites. This Pyrites alternates two or three times with the Quartz.