micROCKScopica - Graphite-bearing Granulite

Polarized light photomicrograph of a thin section of graphitic granulite from Kerala, India.
Nothing can describe the ever-changing nature of our Planet better than a metamorphic rock, like this granulite from S India. 2 billion years ago this was a sediment rich in organic matter on the floor of an ancient sea. 500 million years ago it was deep in the crust of a supercontinent called Gondwana, transformed by extreme temperatures into a granulite rich of graphite (the black strokes of this image). Today the granulite forms some beautiful hills in Kerala, where erosion will start a new cycle. (Sample courtesy of Satish Kumar)