Polarized light photomicrograph a 30-µm-thick “thin section" of " a granulite from Kerala, India. This photo tells us of a geological event half a billion years ago, when extreme heat deep within the Earth gave rise to this crystal formation. Like a stained-glass window, the black graphite cuts across the colorful panels of quartz and feldspar. In this case I actually studiedthis granulite rock from a working quarry in Kerala, India. The microscopic scene that we observe formed at almost 900 °C, when the feldspars crystallized together with graphite in this beautiful intergrowth.