Figure 5

(a.) Transmitted cross-polarized light photomicrograph of fine-grained talc-quartz gangue in specular hematite + pyrite + chalcopyrite ore from the Bingham North Ore Shoot. Note round, high birefringent (second order blue) anhydrite inclusion within pyrite cube on right-hand side, typical of other copper-rich carbonate-hosted massive replacement deposits in other porphyry copper districts. Width of field = 0.69 mm.

(b.) Combination transmitted and reflected plane-polarized light photomicrograph from the Dallas mine, Bisbee district, Arizona. Quartz-chlorite gangue in specular hematite + pyrite + chalcopyrite ore. Silver blades = hematite, pale yellow = pyrite, yellow = chalcopyrite, light pink = quartz, round greenish tan tufts in quartz and chalcopyrite = chlorite, black = holes in chalcopyrite. Width of field = 1.35 mm.
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