Gabbro thin section exhibiting some of the textbook features one would expect from this coarse, mafic igneous rock. The rock is comprised predominately of plagioclase feldspar and pyroxene ( clinopyroxene ) however minor amounts of amphibole and olivine may be present. Under cross polarised light, 2nd order interference colours highlight the clinopyroxene and 1st order grey or white coloured crystals which exhibit frequent twinning distinguish the feldspar. This material comes from Iceland. The glass is 46 x 27 mm in size, supplied in a protective card sleeve with a label, ideal for microscopy, petrology & educational use.