Benitoite Gem Mine, San Benito County

This is the historic Dallas Gem Mine where the discovery of Benitoite was document in 1907. This is the only known location where gem quality benitoite is found making it among the 10 most rare gems on earth. The mine was later renamed the Benitoite Gem Mine by Bill Forrest and Buzz Gray who once owned it. The mine is located on private land and you must gain permission before visiting the property. The mine is located at 714870mE/4023720mN at 4540 feet.

Scroll to the bottom right section of the page for contact information about visiting the mine.

The mineral benitoite is named for its place of discovery: San Benito County, southwest of San Benito Mountain.

The 1907 discovery of benitoite is credited to James Couch who was "grub-staked" by R.W. Dallas to prospect the upper San Benito River area. Mr. Couch told the story that Mr. Dallas sent him to prospect the Idria Quicksilver Mine area. He hitched a small wagon and drove up Los Gatos Creek. He made about 25 miles and camped on Leroy Akers' ranch. The next morning he met Mr. Akers and asked direction to the Idria Mine:

Go back down the canyon about half a mile, then follow a dim road north a couple of miles. From there on it's just a horseback trail and very rough."
After driving the wagon as far as possible, I took the harness off and made a pack for my horse with the bedding and some of the provisions and tools, and hit the upgrade trail.
That evening a little before sundown, I walked into a pine-studded glade as level as a floor. Many of the trees were over a hundred feet high. A nice stream of water was near-by and there was plenty of high grass for my horse. I decided to make this my headquarters for awhile, so I made camp.
The next morning while lazing in bed waiting for the sun to warm the cold morning air, I kept looking around trying to decide which area to start prospecting first. The broken-up look of one particular area close-by across the creek seemed to interest me and I decided that there was a good-looking place to start searching.

The Benitoite Story by David Austin, Oscar Couch and Louis Couch, 1988

Benitoite specimen has crystals to 2.2 cm across and a 1.8 cm gem crystal. J. Veevaert specimens.

What the story failed to make clear is that Mr. Couch traveled up the San Benito River on the New Idria oil road. He went about 1 mile before he past the Florence Mack Mine on his way to Small's Camp, another 3 miles north, where the road forked. At the fork, "a very rough" pack trail continued up Eagle Creek (called Sawmill Creek today), and the wagon road continued west up a canyon then called Sawmill Creek (actually San Benito River headwater), to the ridge near the French Cabin at Agua Buena Spring. From Small's Camp, Mr. Couch took the wagon road for about 4½ miles where he made evening camp before beginning his prospecting the following day on the hillside just north of his camp.

Jim Couch initially thought he discovered a new kind of "blue diamonds" and samples were eventually sent to Dr. George Louderback at the University of California, Berkeley for confirmation. After careful analysis, Dr. Louderback determined that they had found a new mineral, which he named benitoite. R.W. Dallas filed a claim for the Dallas Mining Company in 1914. The Dallas Mining Company built a log cabin there that burned down in the 1951 fire.

Benitoite became the official gemstone of California in October 1985.

Louderback, G. D. "Benitoite, Its Paragenesis and Mode of Occurrence." University of California Publications