Mineral aragonite, chemical composition: CaCO<sub>3</sub>, from collection of <a href="//commons.wikimedia.org/wiki/Category:National_Museum_(Prague)" class="mw-disambig" title="Category:National Museum (Prague)">National Museum</a>, <a href="//commons.wikimedia.org/wiki/Prague" class="mw-redirect" title="Prague">Prague</a>, Czech Republic, originally from <a href="//commons.wikimedia.org/wiki/Slovakia" class="mw-redirect" title="Slovakia">Slovakia</a>
<a href="//commons.wikimedia.org/wiki/User:Karelj" title="User:Karelj">Karelj</a>
2008-04-20
<span class="int-own-work" lang="en">Own work</span>