This weekend, load the trunk with a rock hammer, chisels, a pick and shovel and all the water you can carry.
Your destination is Opal Canyon, the Mojave Desert home of two opal mines that allow visitors to hunt and keep the fabled semiprecious stones.
The Kern County mines are the only known sources of gem-fire opals in California, and one of only three recognized opal fields in the United States. Visitors to the mines pay $2 with the understanding they get to take home all the gems they can find.
Boy Scouts and other civic groups that wish to try their luck at digging for opals pay nothing at all, said Richard Barnett, owner of Barnett Opal Mine.
"A lot of people think (opals) are grapes on a vine that you can just come in and pick up, but it doesn't work that way," said Shirley Barnett, Richard's wife of 42 years. "If it were that easy, we wouldn't have opened this place up."
Opal fanciers quickly discover that the gemstones lie in a finger-like spine of broken basalt known simply as the "dump." The abrasive rubble is so inhospitable that even leather-skinned sidewinder rattlesnakes shy away, leaving opal seekers alone to unearth a gemstone that spits fire and flashes all the iridescence of a rainbow.
"For me it's just as exciting to be out here on a weekend as it was 25 years ago," said Richard Barnett, whose craggy, well-creased hands look like the basalt rocks he scours from sunup to sundown in his spare time.
Added his wife: "You never get over the thrill of finding a good stone."
Fortunately, the good-natured Barnetts are far more accommodating than the hostile desert rocks.
They'll tell you what to look for, where to look for it, how to look and how to care for your stone once you find it. And if you still walk away empty-handed, the Barnetts will usually give you an opal souvenir.
Conversely, if you find a large or rare opal in their mine, you don't have to feel as if you've just picked their pockets.
"I don't care what they take home as long as we get to look at it," Richard said. "I'm tickled to death for 'em."
Shirley, who keeps some opals in a pill bottle she calls her "tranquilizer," has an almost religious attachment to the "Queen of Gems."
"We're not out for the money," she said. "We're out for the pleasure of people enjoying themselves and being able to find something that God put on this Earth to find."
While opals come in a kaleidoscope of colors--from milky porcelains to blacks--those usually found at the Barnett and Nowak mines are either a transparent red-orange (honies) or blue and white (jellies).
But more important than the color is the sparkle, or "fire," that each opal possesses.
Among the Barnetts' luminous treasures is the "Mojave Flame," an opal that glows like coal in a barbecue pit. In 1975, the Opal Miners Assn. valued the stone in excess of $50,000.
"It'll burn your eyes," Richard recently told a group of wide-eyed opal hunters taking a break from the constant clattering of their rock hammers to view his collection. "The blaze in it will darn near start a fire."
Unlike many other gems, opals aren't dependent on being cut with facets to refract light. "It's the only stone I know of that has true color in it," said Richard. "It doesn't reflect from anything else."
Opals were formed in the El Paso Mountains during the last Ice Age as hot geyser water and silica mud percolated through porous volcanic rock, Richard said.
Over thousands of years, the mud and water collected in gas pockets in the rock, then slowly leached out, leaving behind layer after layer of silicates, the minerals found in opals and common glass.
"A (gas) pocket can be any size, from a bucket to the size of a house," Richard said, sounding more like a geologist than a paving contractor in Bakersfield, where he works during the week.
The condensation of thermal mud and silicates is not enough, however, to provide the opal's spark. For a "dead" opal to come alive, the ground in which it grows must be "shifted, shaken and stirred up," Richard said.
"When the layering process is disturbed, you have a completely different molecule structure within the rock," Richard said. "This misalignment of tiny silica beads creates the fire in the stone."
Even armed with such knowledge, neophyte opal miners may still have trouble detecting opals, which bring about $150 a carat.
Margaret Diaz, who owns the Nowak Opal Mine with her husband, Lupe Diaz, and three other couples, said she enjoys showing city miners where to look for the gems.
"You look for the 'honey' in the rock or anything glassy that shines," she said. "Then hold it in the sun and see if it hits. You can see the fire jump, unless, of course, you're wearing sunglasses."
Lupe plays a game of hide-and-seek with visitors as a way to improve their opal-hunting techniques. He salts a bag of worthless calcite crystals with a genuine opal and then asks them to find the stone.