The Mojave Desert is beautiful, vast, and a little bit terrifying for those who’ve never spent time in that kind of region. The vast Mojave makes up a huge chunk of the Southwestern portion of the United States, and its mineral diversity is hard to beat.
So, let’s take a look at some of the exciting possibilities that can be found here. This is your guide to the rocks and minerals of the Mojave Desert.
Rocks and Minerals Found in The Mojave Desert
Geodes are nodules of crystals that are held inside a rounded nodule. These range from spherical to potato-shaped, with the majority on the latter end of things. The Mojave Desert is home to many geodes, including a few places that are unmatched in most of the world.
The majority of geodes you’ll come across are going to have a chalcedony layer with a quartz-filled interior. You may also stumble across the occasional calcite geode, but they’re not quite as common in this region.
These geodes can range from an inch or so across to larger than a basketball, giving a huge variety of different specimens. Each location will have its own quirks, but the majority of these will end up being clear quartz once you’ve got them cracked open. It’s just the way things are.
Fortunately, geode locations are well known and a few are even easily accessible. The area that you’ll want to look for is the Hauser Geode Beds in the Wiley Wells Mining District. There are four large patches known to host geodes here.
If you’re in the area, then you should definitely check them out. Most people can drag one up with even casual digging in any of the four main locations associated with the Hauser Geode Beds. It’s quite a trip, just remember to hydrate and try not to work during peak sunlight hours.
Not unique to the Mojave, but something that’s rarely seen outside of museums. Fulgurites are fused sand left behind after a lightning strike, extending from the initial touch and through the sand. They are sometimes excavated whole, but many times its simply pieces of them that are dug up.
Specifically, the ones found in the Mojave Desert are most often Type I fulgurites, meaning they occur in the sand. Fulgurites are mainly composed of the amorphous silica mineral lechatelierite. This mineral is also the main component of tektites like Libyan Desert Glass and Moldavite, both of which are caused by the high-energy impact of meteorites.
Fulgurites are truly fascinating specimens. Properly excavated fulgurites have been found that are over 10 feet long, but most are considerably smaller. They can be found across many of the flat, open spaces of the desert but they’re also quite hard to detect.
If you’re hoping to discover a fulgurite during your time in the desert, the best place appears to be the area around Imperial Valley, California. That said, you should take an extra look at any tube-shaped, white-ish rocks you find during your time in the desert. Broken fragments of fulgurite are far more common than finding the entire mineraloid structure.
Gold is one of those things that you can’t seem to get away from in California. While the Golden State moniker actually refers to the golden color of the hills during most of the year, it may as well refer to the metal. Gold can be found in the Sierras, in the Central Valley, and even in the depths of the Mojave.
Indeed, the only reason humans decided to head into the landscape in the first place was due to gold. Exploration and mapping were largely meant to help find gold in the desert, with other resources being secondary.
For a casual prospector, the Mojave offers some interesting opportunities. Most of the seasonal creeks and streams that run through the desert can produce some amount of alluvial gold. This gold is often found by dry-panning, there really isn’t a realistic way to bring enough water for the normal prospecting methods to work out there.
You can try around the outskirts of existing mines and those that have been closed in the past. Be extremely wary if you’re around abandoned mines, however. Not only are there the usual dangers of an abandoned mine, but the lumber and other building materials abandoned with the mines often makes them a haven for venomous rattlesnakes.
Gypsum is a very soft mineral, a form of calcium sulfate dihydrate. It’s a common mineral in the desert, found in a few different forms. The mineral itself is very soft, and while it sometimes forms beautiful crystals care must be taken handling them. Gypsum forms include desert roses, selenite, and ramshorn gypsum.
Selenite is the most interesting form for many collectors. It forms into large crystals with high clarity, and it’s a common find among mineral sellers. In particular, it’s easy to find the longer crystals, known colloquially as wands. It can be found East of Las Vegas, near Lake Mead.
More commonly found are desert roses, which are intricate growths of bladed gypsum crystals. These are different from the sandstone rose rocks found in Oklahoma, which are usually formed of barite mixed with sand particles. They are more often just clusters of crystals, rather than actually resembling a rose. They turn up anywhere gypsum is found in the Mojave region.
Gypsum is more than just pretty. It’s also a vital part of our modern world since it’s used in chemical and industrial processes and even as a building material. A lot of gypsum ends up pressed together between paper, you probably know it as sheetrock or drywall. It’s an interesting mineral, and one worth seeking out in its more exotic forms.
Quartz is preposterously common on our planet. After all, it’s simply the macrocrystalline form of silica. The most commonly seen form is as clear, high clarity crystals with one terminated point. You’re unlikely to find these out in the Mojave, but there are still many forms present for those who know where to look.
There are areas in the desert that have a ton of white rocks, usually with moss growing underneath them. This is milky quartz, a fracture filled variant of the crystals we normally see. The inclusions actually keep light down and the light color causes them to reflect heat, which is why cyanobacteria and certain mosses seem to thrive underneath them.
For high-clarity crystals, you’ll want to take a look into finding geodes. The majority of loose material haunting the desolate spaces of the Mojave can be interesting, but usually not interesting enough to end up in your pack. Especially when you’re hiking and hounding, every ounce counts when you’re hiking in the desert. These stones are scattered across most of the desert, easily identifiable by their white color.
On the other hand, you can still find amethyst in the Mojave if that’s what you’re after. The purple-colored quartz is common near the Purple Heart Mine in the Kingston Range, which is also one of the few places to find clear quartz crystals. The amethyst here is a bit redder than most Brazilian material as well, making it a good find even for those who already have a few pieces.
Turquoise is a valuable gemstone, and many people dream of finding a large chunk. Love it or hate it, it’s extremely valuable and an interesting mineral in its own right. This copper-laden stone is a staple of Southwestern style jewelry and older stock can reach preposterous prices.
The truth is that most really good pockets of turquoise have either been mined out or someone is working a claim there. People are often fascinated with the provenance and experts can spend hours trying to determine which mine a turquoise cabochon came from.
Turquoise usually occurs in small pockets, which makes it easy to run a mine out over the course of a few years. This naturally limits the amount in circulation, driving a high price. Please be aware that “Mohave Turquoise” is a trade name for a resin conglomerate, it’s not just a misspelled version of Mojave.
Still, there are a few areas you can probably find some. Just west of Turquoise Mountain is the Turquoise Mining Area in San Bernadino County. This is an excellent place to search for an amateur, but the best locations are always held privately.
Whatever you might call an individual piece, cryptocrystalline silica is highly sought after and it exists by the bucket in the Mojave. It’s just a matter of finding one that suits your tastes. All three forms are present to some degree in the Mojave Desert, with agate and jasper being common finds in creek beds.
The jasper present in the desert ranges from simple single-colored pieces to some jaw-dropping specimens with tons of bright colors. It just depends on the area and the individual pieces of stone. They’re easily found in creek beds near towns, and out in the desert.
Agates also have a wide variety in the desert, as you’d expect from a region this size. You can find them in the usual places, but there’s one thing that many people miss. In areas where you’re not having any luck on the surface dig down around shrubs and look through the roots. They often capture pieces of agate or jasper for years or decades, protecting them from the prying eyes of casual rockhounds.
Lastly, in the Southeastern portion of Kern County you can occasionally find “Mojave Blue Quartz.” This is actually a light blue form of chalcedony, often broken pieces of a larger agate with signs of banding still present. I’ve been unable to find the exact location, but there’s been some interesting discussion on the matter.
Tourmaline is a relatively common gemstone, it’s the varieties that will get you. While the Mojave hasn’t yielded any rubellite or indicolite specimens that I’m aware of, you can still find tourmaline crystals of a few different varieties spread throughout the hills and canyons.
The most famous deposits, like the Himalaya Mine, are on private land. In that case, it’s not only on private land but also requires permission from others just to pass through to get there. This area yields great green and pink tourmaline, often with a decent size in addition to good color saturation.
Of course, that begs the question of where an amateur with no connections can go to find tourmaline crystals. The answer is simple: you’ll want to look in the pegmatites that are present along the western edge of the desert. In particular, they can be found in San Diego, San Bernadino, and Riverside counties where the mountains meet the desert.
Most of what you find will be schorl, which is black and not worth as much as the majority of tourmaline. Occasional crystals in other colors will be found, and I’d keep it to myself if I found a place where high color saturation crystals can be found regularly. It’s truly a gem of the desert and the leading gem export from California!
9. Fire Agate
Fire agate is still chalcedony, as the ones described above, but there’s a slight difference. Fire agate is usually botryoidal in form, and inside of it are shimmering layers of limonite and iron that create a 3D, iridescent structure when the surface has been polished. This structure is very thin, which makes cutting fire agates an art that requires experience.
It varies greatly between pieces. Some will show only a red-to-brown shimmer, while others have a complex rainbow contained under the surface layers of chalcedony. Fire agates value varies by color, size, and formation. High-grade pieces can be worth hundreds to thousands of dollars when cut.
And that’s the rub of it: it’s hard to grade fire agate without cutting it, but cutting it is a special skill that not every lapidary possesses. You can learn easily enough, but I’d expect to ruin a stone or two along the way. If you stick with it? The world of fire agates is incredible and the skill required will transfer to other tricky stones very well.
Fire agate is spread across SoCal, New Mexico, and Arizona. The highest quality deposits appear to be in Arizona. The Black Hills Rockhound Area and the Round Mountain Rockhound Area are both in Arizona and provide visitors with a great location to find their own fire agate.