Nice lustrous dark blue azurite crystals to 13 mm across, sitting on a rhyolite matrix. There is damage to a couple of crystals, as can be seen in the photo. The underground workings of this mine have now reached the sulfide zone, and it is unlikely that significant additional secondary copper minerals (like azurites) will be produced from this mine in the future. See the article on this occurrence in the special “Mexico V” issue of the Mineralogical Record, Vol. 39, No. 6, November – December, 2008, pages 25-34.