Skeletal pyroxene (green) and olivine (colorless) crystals in a Etruscan Furnace Slag, Campiglia Marittima (Livorno), Italy. Plane polarized light image, magnification 10x (Field of view = 2mm)
<a href="//commons.wikimedia.org/wiki/User:Strekeisen" title="User:Strekeisen">Strekeisen</a>
<span class="int-own-work" lang="en">Own work</span>