Figure 1
Reflected plane polarized light photomicrograph of rhythmic specular hematite // pyrite-chalcopyrite layering in hematite-bearing ore from the Bingham north ore shoot. Note how layering is the result of both mineralogical and grain size variations. The rhythmic layering also locally shows hematite blades growing perpendicular to layers. The non-opaque gangue (black) is talc (+ trace quartz). Pyrite shows weakly developed sieve texture, a common feature in all three districts studied for this report. Silver blades = hematite, pale yellow cubes = pyrite, yellow interstitial = chalcopyrite. Width of field = 2.69 mm.