The 72nd Gem-O-Rama at Searles Lake in Trona, California.


On the second weekend in October—for over seventy-five years—Searles Valley Minerals (SVM) hosts Gem-O-Rama, a gem and mineral collecting extravaganza for the general public at Searles Lake in Trona, California. Organized by the local Searles Lake Gem and Mineral Society, rockhounding enthusiasts from around the world attend with a good deal of the participants coming from the greater Los Angeles area.

Trona, population 2,742, is overrun with nearly 3,000 people converging for this well-choreographed weekend event that is hosted and directed by the local citizenry and employees of SVM. Attendees are from a mix of cultural and economic backgrounds of varying age and experience.“Desert rat” prospectors—who appear to have just come off some remote gold or silver claim out in the surrounding backcountry—dig alongside coifed housewives accompanying their kids in an effort to reap Searles lakebed’s saline mineral treasures. Although a few folks search for rare and expensive specimens to sell for hundreds of dollars in secondary markets, the majority of participants are there for good ole dirty fun and a chance to hang out in a remote part of the Mojave Desert. It is a unique, festive experience to say the least.

The Mud Run

Originally begun in 1941, Gem-O-Rama is organized into three field trips throughout the weekend. The first is Saturday’s Mud Run, where tons of rich, black gooey earth is dug from the overburden mud layer found about ten to twenty feet below the static brine lakebed surface. Huge piles are dumped—more than 150 tons—for the participants to rummage through in hopes of finding six-sided flat “barrel” hanksite crystals up to four inches across. These specimens are translucent to transparent in color, varying from pale yellow-gray to colorless with a partial or completely flat “basal pinacoid” end termination. Also found within the occluded mud are larger “twinned” hanksite formations where two or more crystals are joined together.[1] Massive trona clusters exhibiting clear, sharp “bladed” crystal clusters along with halite, smaller thenardite specimens, sulfohalite, and borax (which turns powdery white upon exposure to air) may also be collected during this field trip.[2]

Once located, collectors must scrub their specimens in a brine bath to remove the mud to expose their shiny surfaces.[3] The SVM provides long cleaning troughs where participants work shoulder to shoulder collectively washing their finds, conversing as they scrub, creating a congenial, shared experience for everyone involved. To preserve their finds, collectors are advised to dry specimens thoroughly and preserve them with a light coat of mineral oil.

Hanksite was first identified by George Hidden in 1885 but was named to honor American geologist Henry Garber Hanks. It is one of the few minerals to contain both carbonate and sulfate ion groups. Searles Lake contains 99 percent of the world’s hanksite. Lake Katwe in Uganda is the only other location outside of Searles Lake where the mineral is known to exist. There are no industrial uses for hanksite. New Age practitioners suggest that this mineral “provides insight, perception, adeptness and awareness,” aids in meditation and corresponds to the Solar Plexus Chakra.

The Blow Hole

Occurring after Saturday’s lunch break, The Blow Hole field trip allows participants to collect a cornucopia of crystals and minerals spewed across the lakebed. In preparation, the SVM selects a prime location several weeks before the event that is suspected to yield the best possible crystals, but also allows the public nearby parking access. Licensed explosive technicians working with SVM blast a series of holes down to about twenty-five to forty feet below the lakebed. The treasures are then brought up to the surface by pumping compressed air down into the blow holes thus creating enough pressure to force the material up and onto the lakebed. Although this preparation is done in advance, a demonstration of the actual process is held for the audience to view. Participants are asked to not begin collecting until the demonstration is completed for safety reasons. A variety of crystal specimens, including fairly common terminated hanksite and the more rare and elusive sulfohalite, which look like tiny, conjoined double-ended pyramids, may be collected effortlessly during this field trip. Sulfohalite is found in only 0.1 percent of the crystals present at the site.

Trona or Bust! gemo_1 gemo_2 gemo_3 gemo_4 gemo_5 A mural celebrating Trona’s borax history by local artist T. Scott Sayre. gemo_7 gemo_8 gemo_9 gemo_10 gemo_11 gemo_12 gemo_13
Searles Valley Mineral technicians "blowing" minerals from below the surface of the lakebed for participants to collect.

The Pink Halite Sunday Field Trip

The lovely pink halite found at Searles Lake is its second most abundant saline mineral. It forms annually after winter floodwaters begin to recede and evaporate slowly, producing cubic-shaped salt crystals up to two inches across. The pink to reddish coloring of this halite is due to the halophilic or salt-loving bacteria present in the brine that, as they die, produce a warm colorization present in many desert salt ponds. Halobacteria are a microscopic, rod-shaped bacteria that produces a red carotenoid pigment similar to beta carotene. Some bacteria become trapped during the halite crystallization process, thus yielding its distinctive pink coloring. Other halite found at Searles may be a glowing pale-green color to simmering aqua blue, the result of algae contamination.

Pink halite is found close to the surface in brine pools about six to twelve inches under a hard salt ledge. Only the halite near the surface of a pool that has been protected against direct sunlight retains its pink/red color. Collecting it requires wading through the brine ponds and some physical effort to break through the hard salt crust with a pickaxe or a steel pole to reveal and dislodge the crystal formations found submerged below.

Collection equipment is available for a modest rental price at the Searles Lake Gem and Mineral Society’s building in town. The two Saturday field trips, The Mud Run and The Blow Hole, cost $15 per vehicle, with Sunday’s Pink Halite field trip costing $20. Other events include a lapidary and mineral show plus a pancake breakfast. For more information on next year’s Gem-O-Rama visit:

On July 4th, 2019, Trona experienced a 6.4 magnitude earthquake. A giant 7.1 magnitude event followed the very next day with hundreds of smaller after shocks continuing over subsequent weeks. Property and infrastructure damage was extensive—compelling Gem-O-Rama’s organizers to cancel the popular October event for the first time in seventy-eight years.

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[1] Twinning occurs from a flaw during the crystallization process, resulting in two or more crystals appearing to have grown out from each other like conjoined twins.

[2] Trona, the town’s namesake, is the second most abundant saline mineral found at Searles Dry Lake, with thenardite the second most abundant sulfate mineral found there.

[3] Because these saline minerals are soluble in water, they must be washed and cleaned in brine, otherwise their surfaces will become etched or they will simply dissolve into solution over time.

For further reading on the various minerals found at Searles Lake visit Search in Locality for “Searles Lake, San Bernardino County, CA” or a specific mineral name.

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