Fist-sized specimen of coarse-grained and crudely banded ore from the now closed Nanisivik MVT (Mississippi Valley-Type) lead-zinc mine on Baffin Island, Nunavut Territory, Canada. Dark brown to black bands = sphalerite (zinc sulphide), yellow = pyrite (iron sulphide) and white = dolomite (calcium-magnesium carbonate).
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/31856336@N03">Mike Beauregard</a>
CC BY 2.0
<a href="//commons.wikimedia.org/wiki/Flickr" class="mw-redirect" title="Flickr">Flickr</a>: <a rel="nofollow" class="external text" href="https://www.flickr.com/photos/31856336@N03/3108681427">Nanisivik Ore</a>