<p><a href="//commons.wikimedia.org/wiki/User:Siim" title="User:Siim">Siim Sepp</a>, 2006
</p>
Volcanic rock andesite. Photomicrograph with crossed polars. The width of the view is approximately 0,15 cm. Porphyritic texture. Main phenocrysts are plagioclase, hornblende and magnetite.  Groundmass is composed of volcanic glass, plagioclase, hornblende, magnetite and biotite.
No machine-readable author provided. <a href="//commons.wikimedia.org/wiki/User:Siim" title="User:Siim">Siim</a> assumed (based on copyright claims).
CC BY-SA 3.0
No machine-readable source provided. Own work assumed (based on copyright claims).