Fast forward to present day and the XRF has come of age. Pull the trigger on the hand-held device and you get a nearly instant assay of the surface of a rock.

Fortunately, there are products on the market that can address these problems and make a small-scale mining operation feasible.

Another little gem of equipment he built was a nifty sample splitter. In order to get accurate assays, you need to have really good, representative samples for the assayer to process.

Fascinated by the sapphires—and the gold that occured with them—he was soon buying parcels of property and setting up his own commercial-scale gravel processing plants.

The other opportunity that I see is in seeking unusual types of deposits. Specifically, the prospector would be searching for the stuff no one (or almost no one) is searching for. These deposits are effectively hiding in plain view.