Art of Gold
During their raids, police found gold-processing equipment at Joe Hardesty’s two mines. Digging for gold can be quite lucrative for a sand-and-gravel outfit in the western Sierras. Gold-rich placer deposits in the Sierra—known in geo-speak as auriferous gravels—can yield as much as 0.005 ounces of gold per ton of rock, said Donald Drysdale, a spokesman for the State Mining & Geology Board.
“One needs to move a lot of earth in those circumstances to make money, assuming 100 percent recovery, which is seldom the case,” Drysdale said in an email.
However, a 1970 book, Gold Districts of California, by William B. Clark of the California Division of Mines and Geology, said ore from the Deep Blue Lead in Placerville is capable of yielding one-fourth to one-seventh of an ounce of gold per ton, exceeding Drydale’s estimates by a factor of between 28 and 50.
Clark said the Deep Blue Lead was one of the richest and best known veins in the area. “The lode-gold deposits are massive quartz veins as much as 20 feet thick with numerous parallel stringers,” he wrote.
Hardesty denies that he is mining gold. But how much gold could he have been finding, hypothetically, from moving a lot of earth at his two mines?
You do the math. Hardesty reported that his mines produced approximately a half-million tons or more of sand and gravel every year, yielding about 2,500 potential ounces of gold, if he truly extracted the ore at the rate Drysdale said was possible.
But using Clark’s higher estimate, Hardesty could have mined 71,000 to 125,000 ounces of gold per year.
An ounce of gold sells for about $1,700 on the commodity markets these days.
Using Drysdale’s rate, Hardesty’s annual gold sales could have exceeded $4.25 million. Using Clark’s estimate, such a mine would have yielded between $120 million and $212 million worth of gold each year.