Orbicular Granite

The markings on the rock aren’t man-made; they’re created by geological processes. This type of rock formation is called ‘orbicular granite’.  Occurrences of such ‘orbicular granite is very rare. The fascinating rock formation on the above picture is located near the town of Calder in Chile. This unusual plutonic rock type is also known as ‘orbicular rock or orbiculite’. The uniqueness of this rock is due to orbicules – concentrically layered, spherical structures, probably formed through nucleation around a grain in a cooling magma chamber.