Feldspars with intergrown graphite
This image tells of a geological event half a billion years ago, when extreme heat deep within the Earth gave rise to this crystal formation of quartz and feldspar. This rock, from a working quarry in Kerala, India, was studied with colleague Satish Kumar. Petrographic section observed by polarized light microscopy.
Submitted by: Bernardo Cesare, University of Padova, Padova, Italy