Benitoite Mining Company gem hunts

The screening field on Los Gatos Road

A white buffalo stands in the parking lot at the Historic Old Road Camp, fifteen miles out Los Gatos Road west of Coalinga. The company tells drivers to watch for it and to turn in just before it. It also warns that the other approach, by Highway 25 and Coalinga Road, is not well maintained. Beyond the lot is the screening field. Ore from the Benitoite Gem mine in San Benito County is dumped there for visitors to sort. Nobody goes into the mine. The company’s FAQ puts it this way: “It’s nice and easy, no spelunking required!”

The camp supplies screens, shovels, washing tables, safety gloves, and clear UV-protective glasses. Staff show newcomers what to do and what to look for, and they identify finds through the day. Visitors bring their own lunches, drinks, and lawn chairs. In summer they bring hats, sunblock, and pop-up canopies. In winter they bring warm clothes and mud boots. Rock hammers and pets are not allowed. Diggers stay between the screening field and the parking lot, and children may play freely nearby. A day runs from 9 a.m. to 3 p.m., and there is no limit on how much material a person may wash. Each admission allows one quart-sized bag of finds to take home. A notice warns that serpentine is present in the digging material and invites diggers to bring masks.

The company names four minerals as specific to the site: benitoite, neptunite, joaquinite, and natrolite. Benitoite, the FAQ says, is “a small gemstone, think diamond size.” Diggers carry their concentrate into the UV room. Under short-wave ultraviolet light, benitoite fluoresces bright blue to bluish white. The rarer clear and white crystals glow red or pink under long-wave light. “Most people find something, but the trick is finding something good,” the FAQ says. It puts the odds of leaving with a stone of value at about 1 in 20.

Dave Schreiner owns the mine. In 2021 he told BenitoLink that trespassers had forced him to lock the entrance and put up security cameras. He added that the ground is also home to rattlesnakes and poisonous scorpions. Because the public cannot enter the mine, he opened the camp in 2015, across the Fresno County line. “We have people who come every weekend,” he said, “and it has really turned into a fun community event.” He also warned that the work “is pretty demanding.”

Blue crystals on a San Benito hillside

Most accounts agree on the core of the discovery. A prospector, staked by a Coalinga oil man, found blue crystals near the headwaters of the San Benito River in 1907 and took them for sapphires. The details vary from source to source.

The company’s history is by Leza Junnila, who grew up at the New Idria Mines. She gives the prospector’s name as James Couch, a rancher near Coalinga who raised produce and chickens. When the economy slowed in 1907, he went prospecting south of New Idria. R.W. Dallas grubstaked him. Couch rode up the Los Gatos Creek canyon road and made camp at nightfall on the headwaters of the San Benito, where there was grass and water. Morning light showed a small rocky exposure on the north side of the canyon. In it was an eroded pocket of white rock with bright blue crystals sticking out all over. “Blue crystals were lying all over the ground,” Couch said. He went straight back to Coalinga to show Dallas. Later that week he rode three days each way on horseback to Hollister, the county seat, to file a federal mining claim. Local miners Frank Nunez and Joe Larios, Junnila writes, always spoke fondly of him.

The other sources differ:

• Collector’s Edge Minerals dates the find to February 1907. A stock certificate for the Dallas Mining Company bears the same month.
• BenitoLink names the prospector James Marshall Crouch. It says mining speculators Roderick Dallas and Thomas Sanders staked him $25 to explore the Diablo Range.
• One museum account places the find in December 1907. It calls the discovery claims complex, and its most widely accepted version begins with Couch as a failed melon farmer.
• Another source gives 1906.
• George Louderback, by another account, first credited L. B. Hawkins and T. E. Sanders as discoverers.
• Oscar Couch, the prospector’s eldest son, published The Benitoite Story in 1961, arguing that his father deserved sole credit.

Junnila’s history describes what happened next. Once the stone proved to be a new species, Dallas took tighter control, and Couch “was manipulated out of the mine and became nothing more than a hired hand.” A photograph of the cabin built at the Dallas Gem mine in 1907 shows Couch second from the left.

A professor from Berkeley and a man from Tiffany’s

The crystals went to George D. Louderback, a mineralogy professor at the University of California at Berkeley. He saw that they were neither sapphire nor spinel. On July 19, 1907, he visited the mine with G. Eacret and confirmed the find. On July 31 he wrote in the university’s Bulletin of the Department of Geology that “the progress of the investigation has shown that it is a new mineral species.” He named it benitoite, after San Benito County, according to Collector’s Edge. Other sources say he named it for the river, the county, and the nearby mountain range, or for the river that runs through the claim. The California State Capitol Museum says the name came two years after the discovery.

Louderback called the black mineral found with the benitoite “carlosite,” after nearby San Carlos peak. He later learned it was neptunite, first described in Greenland in 1893. He came back that October to study the geology. On August 12, 1908, he returned with Eacret and took the first photographs of benitoite for his full article.

The news ran in papers across the country. BenitoLink reports that Tiffany & Co. placed one of the first large orders. Collector’s Edge tells it differently. George Kunz of Tiffany’s in New York was among those who rushed to the site seeking exclusive marketing rights, and Eacret, of Shreve and Company in San Francisco, won them.

According to the Dallas Mining Company diary, active mining began in July 1907. Dallas built a camp and worked an open cut and a short tunnel driven into the blueschist outcrop. For about five years the vein yielded thousands of gemstones. Junnila adds that miners of the time did not know how to etch away the natrolite to free the benitoite, so thousands of stones were broken in recovery.

Rock gardens, bulldozers, and a fire hose

In 1912 the market slackened, and Dallas, in financial trouble, closed the mine. The equipment was auctioned in October 1913 and the property vacated. Mineral patent papers were issued in 1917. The old county road passed right by the workings. Junnila writes that collectors hauled off natrolite boulders studded with broken crystals for their rock gardens. Frank Nunez’s grandmother kept one at Sawmill Creek. A forest fire burned her cabin, and the garden was forgotten until benitoite grew expensive, by which time the spot was lost and overgrown. Another fire took the log cabin and corrals at the mine.

After 1920 B. Suit of the San Benito Gem Company leased the ground, but little work was done. In 1933 M. Dunn reopened the property and removed a lot of material. Junnila records that Dunn’s Packard touring car went off the road one bad winter, and that she and her brothers later recovered its brass radiator from a canyon near San Benito Mountain. Mineral collector Art Pawson visited in 1937, while the mine was idle. His daughter, geology teacher Suzie Harlow, still shows the specimens he brought home. “The most joy I get from my dad’s collection is letting people see this stone they have never seen before,” she told BenitoLink.

The Dallas family leased the mine to a succession of operators. Miller Hotchkiss of Firebaugh bulldozed the open cuts, in the 1940s by one account and the early 1950s by Junnila’s. About 1952 Clarence Cole, an Oakland mineral dealer, took the lease and reopened the original pit with bulldozer and dynamite. Cole kept big plates of benitoite crystals in his shop windows. He sold faceted stones to miners at New Idria, among them store manager Virginia Shadduck. Junnila writes that her family learned of the mine by talking with Cole at that store. Josephine Scripps, a mineral collector, leased the mine for a year. In 1957 Francis Jones found a mineral there that was identified in 1977 as a new species, jonesite.

Cole died in 1967, and the lease passed to Bill Forrest and Elvis “Buzz” Gray. In 1970 they began washing the old dumps with water pumped uphill through a fire hose. They brought in mechanized recovery in 1982. Collector’s Edge says they bought the property from the Dallas family in 1987, and Junnila says it was about ten years after the lease. On October 1, 1985, the California Legislature designated benitoite the state gem. In the mid-1990s Kennecott Corporation leased the mine, drilled cores, and sampled the surrounding country, but its board chose a mica mine in Arizona instead. In the spring of 1997 Forrest and Gray, working with larger machinery, found a productive area downslope of the open pit.

In 2000 Benitoite Mining Inc., affiliated with Collector’s Edge Minerals of Golden, Colorado, bought the property. Brian Lees brought in a mining crew for five winters. In the spring of 2002 the company installed a processing plant with a hopper, conveyor, washing screens, and jigs, where crews hand-picked specimens off the belt. Old tunnels were opened and dug out to about 9 meters, where the benitoite gave way to bare natrolite.

Schreiner bought the mine in 2005. The camp opened in 2015 as the California State Gem Mine and took the name Benitoite Mining Company in 2020. “The mine is still active,” Schreiner told BenitoLink in 2021, “but we really have no idea how much benitoite is left.”