Igneous rock diorite. Photomicrograph with plane polarized light. The width of the view is approximately 0,2 cm. Main minerals are plagioclase (white), hornblende (green) and magnetite (black). Plagioclase is sericitic (covered with fine muscovite flakes) because of hydrothermal alteration.
<a href="//commons.wikimedia.org/wiki/User:Siim" title="User:Siim">Siim Sepp</a>, 2006
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>