<a href="https://en.wikipedia.org/wiki/Acanthite" class="extiw" title="en:Acanthite">Acanthite</a> - Locality: Chispas Mine (Pedrazzini mine), Arizpe, Mun. de Arizpe, Sonora, Mexico - Scale at bottom of image is one inch with a rule at one cm.
<a rel="nofollow" class="external text" href="http://www.mindat.org/user-2982.html#0">Rock Currier</a>
CC BY 3.0
<a rel="nofollow" class="external free" href="http://www.mindat.org/photo-216115.html">http://www.mindat.org/photo-216115.html</a>