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:
“Your wits can’t thicken in that soft moist air, on those white springy roads, in those misty rushes and brown bogs, on those hillsides of granite rocks and magenta heather. You’ve no such colours in the sky, no such lure in the distances, no such sadness in the evenings. Oh the dreaming! the dreaming! the torturing, heart-scalding, never satisfying dreaming, dreaming, dreaming, dreaming!”
—George Bernard Shaw (1856–1950)