This very considerable variation in thickness will be found to be owing to the folds or plications of the vein, to which we shall hereafter make more particular allusion The minerals associated with the quartz in this vein, especially the cuprite and mispickel, are found most abundantly upon the foot-wall side, or underside of the quartz itself.— The Atlantic Monthly, Volume 13, No. 79, May, 1864
The underlying slate is filled with bunches of mispickel, not distributed in a sheet, or in any particular order, so far as yet observed, but developed throughout the slate, and varying in size from that of small nuts to many pounds in weight, masses of over fifty pounds having been frequently taken out.— The Atlantic Monthly, Volume 13, No. 79, May, 1864
But the cost of the quartz cannot be so much by one-half as that named above; and there is the additional value of gold from the pyrites and mispickel, as well as probably fifteen per cent, saving on the total amount of gold produced by improved methods of working The reason why so little alluvial gold is to be found throughout this district may be very simply and concisely stated.— The Atlantic Monthly, Volume 13, No. 79, May, 1864
Iron is found combined with sulphur in pyrrhotine and pyrites, and together with arsenic in mispickel.— A Text-book of Assaying: For the Use of Those Connected with Mines.
Pyrites, mispickel, &c., are insoluble in hydrochloric acid, but they are readily attacked by nitric acid.— A Text-book of Assaying: For the Use of Those Connected with Mines.

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