Finding Diamonds in California

Uncut diamonds

From the earliest days of the California Gold Rush diamonds were found in the tailraces of sluice boxes that were used for gold washing.  Diamonds were found not only in recent stream gravels but much older gravel that was buried under layers of lave and tuff from ancient volcanic activity as fossilized stream channels that ran along the mountains from north to south.  These stream channels indicated an ancient stream flow that was almost at right angles to the present day flow.

The biggest problem with California diamonds is there just are not enough to make going after them profitable. Most of the stones have been found as a result of gold washing operations in both present day streams and in the fossilized beds of earlier streams. Many of the diamonds were destroyed by the use of stamp mills used the breakup the gold ore retrieved from the fossilized streambeds. Their presence was noted as fragments seen in the gold ore. The diamonds that were recovered from ore were for the most part small or industrial grade diamonds.

As early as 1853 diamonds were discovered on top of Table Mtn. about thirteen miles north of Oroville on state Highway 70 close to the ghost town of Cherokee.  It was in the gold diggings surrounding the town that reportedly more then 300 diamonds were found most of them being of industrial grade.  Claims have been made that at the time this was the largest discovery of diamonds made in North America.  This has been exceeded with the discovery of several diamond producing areas in Canada.

Cherokee was the site of the only diamond mine in California, and it was here the first diamonds were found.  Mike Maher discovered a perfect blue diamond when he was cleaning out his sluice box in 1866.  Other diamonds were found here with one of them weighing six carets, but because gold was the primary concern it is unknown how many millions of dollars worth were discarded with the mine tailings produced by the hydraulicing for gold with high pressure jets of water that washed away the gold ore.  

The fact that diamonds do occur in California is well attested to in newspapers and scientific journals.  In some cases however it is readily apparent that many of these so-called diamonds were in fact quartz crystals that had become rounded because of stream action.  One such quartz crystal had been used as a marker in a game of marbles where it show several percussion marks that were the result of being hit by marbles.  A diamond would not show such percussion marks, but would rather cleave into pieces instead waiting to be found in the sluice boxes at work in the area.