The Contact: Inside Granite (2015): This is a pretty faithful view of what you’d see in a microscope when looking in polarized light at a thin section of a granitic rock, like those from the Sierra Nevada. Much of the gray and white is supposed to be quartz or potassium feldspar (microcline; probably the gray at the bottom). There is a striped piece of plagioclase feldspar on the right, and what looks like biotite mica crystals in shades of orange, red, and green on the left. The black may be an oxide mineral – I’m not sure. I love how Johnson uses the stitching and color here to emphasize both the minerals’ microscopic structural features (cleavage planes of the mica, twin planes in the plagioclase) and the way the minerals’ shades change as you turn the microscope stage (called extinction; quartz and microcline fade in and out of black in a characteristic wave-like or patchy way – see the microcline crystal at the bottom).