The hunt for gold on a Colorado mine dump to be reclaimed from the gold Rush ers by David Emslie. 

Sampling and evaluation of a historic tailing pile. Ore reserve pile loaded with gold Rush era ore. Samples are x-rayed and found to have values from 1/4 oz to 80 oz per ton gold. And a trace to 4.5 kilos of silver too the ton.
Free Milling gold was found in the specimens.
Lessons on geology. Mineral to be found. How to evaluate for values and testing and breaking rock to see inside. A lot of information is detailed in this video on what to look for to consider mining a gold Rush era dump for reclamation and processing.