Orbicular granite (also known as orbicular rock or orbiculite) is an uncommon plutonic rock type which is usually granitic in composition. These rocks have a unique appearance due to orbicules - concentrically layered, spheroidal structures, probably formed through nucleation around a grain in a cooling magma chamber. Almost one third of known orbicular rock occurrences are from Finland. The occurrences are usually very small.
Read more about Orbicular Granite: South African Occurrence, Places With Orbicular Granites
Famous quotes containing the word granite:
“Paper is soft and ink is fluid; it might be better if some pages of this chronicle could be written on chips of granite at the point of steel.”
—E. M. Almedingen (b. 1898–?)