Nevada - Clark County
From the discovery of the great Comstock Load in 1859 to the last Nevada mineral rush in 1928, numerous prospectors have been combing every hill and canyon for signs of gold and silver ore. Thousands of strikes have been made, a few worth millions and many worthless, but in most cases the ores were gold, silver, and copper. A few people realized what variety of metals there was in Nevada though, and some strikes were made in lead, manganese, nickel and marble. There was even a platinum mine - but no one ever expected to find diamonds.
In 1872, as the story goes, one of Nevada's drifting prospectors headed into the southernmost part of Lincoln (now Clark) County to see what they could find. After spending the night at the Gass Ranch, just north of present downtown Las Vegas, he started due south into the McCullough Mountains. The prospector had covered about 30 miles when he ran across a streak of blue clay in a volcanic formation. Thinking there might be something in the deposit, he took samples and panned them. When all that showed up were a few crystals, he continued on his way.
Quite some time later the prospector happened to show the crystals to a jeweler who informed him they were actually diamonds. Jubilant over this unusual find, the prospector gave most of the stones away to friends, confident that he could always return and work his claim. When he traveled back into the McCullough's though, he never could locate the blue clay again. He searched and searched, but at the time of the discovery he had thought the clay to be worthless. He had not marked its location in his mind, and he never saw it again.
The story was often told in the mining camps of Southern Nevada, but as diamonds had never before been found within the state, there were very few people who believed the tale. Then in July 1905, E. L. Hews located a diamond mine three and a half miles southeast of Tonopah. All of the sudden Nevada experienced a "diamond rush" with hundreds of people flocking to the claims situated on the Tonopah-Silver Bow road. But the excitement was short-lived and the boom died when experts concluded that the diamonds were of poor grade and practically worthless.
When the existence of diamonds in Nevada an accepted fact, the old story of the lost diamond mine in Clark County is now looked upon more favorably. There indeed may be a vein of diamonds in the McCullough Mountains, but it is also possible that, as in the rush of 1905, the stones may be completely worthless. On the other hand, no one knows what treasures might lie beneath the surface of that thin streak of blue clay.
Nevada Lost Mines & Buried Treasure - By Douglas McDonald, Nevada Publications, 1981, Page 72-73.
The Society has yet to research this claim.