Nevada Opals

Mining for opals is an interesting and rewarding experience even when the deposits can be illusive and difficult to find. This is especially true when prospecting under the desert heat of Nevada and just a little taste is plenty enough to turn an hour excursion into a day's event. Truthfully, it was difficult to walk away from mining at the end of the day even while hot, sweaty, and physically tired from moving overburden all day. The reward was worth it for our first time mining opal; loads of knowledge and beautiful specimens.

Strategy and care is necessary while chipping away at rock that easily crumbles. Going too quickly risks hitting through an opal and fragmenting it into smaller pieces. However, following lines of white silica formation does help to locate the gems and exactly how the specimens pictured here were found. While digging for opals, we also found a few nice specimens of petrified wood well-preserved with ash an silica in tact. We hoped to find a nice example of opalized-wood though we were still thrilled for the discoveries.




Another goal of the day was to find the specimens as pictured, displaying the silica formation and opal deposit tube structure in the rock itself. Often enough opal is shown in an iridescent form, polished, cut, and presented as jewelry. It's really quite amazing how delicate the rock and gems are while surviving thousands and thousands of years. We placed these specimens directly in water when found and let them slowly dry naturally in attempt to preserve the structure.

Pyrite Crystals

The promise of finding gold has too often been thwarted by glittering, multifaceted cuboid crystals known as pyrite. There are stark contrasts between the two minerals when closely examined, but from a distance on a long hot day, it's understandable to see why pyrite could be mistaken for gold. In the right light, pyrite glimmers like gold and easily stands out in piles of excavated dirt. It has fooled many treasure hunters around the world into thinking they finally uncovered something of value for tedious hard work. For this, the reflective mineral acquired the name, Fool's Gold, adding yet another barrier between a man's desire of a lavish lifestyle.

Pyrite is commonly found in areas associated to gold such as quartz deposits and is sometimes known to include very small amounts of gold through a process of substitution. However, the difference in minerals is significant by valuation. Pyrite is formed as a cuboid crystal structure which is distinctly evident upon close inspection. It is also a harder material and this is a reason why people may bite down on the minerals, to assess how malleable the substance is. Gold is softer, easier to work, and a bite will leave an impression when compared to pyrite.


Despite the fact it is desired less than gold, and is not quite as versatile for modern applications, pyrite is still a fascinating mineral. The crystal formation demonstrates nature's ability of creating complex ordered structures under the right conditions. Though it is common to find cuboid shapes in the mineral, pyrite can also be formed with dodecahedron and quasicrystal shapes. Looking closely at pyrite is a glimpse into a window of nature's mathematical capabilities, even if found when expecting to find gold.

Megalodon Tooth

 An immediate thought when holding a small megalodon tooth for the first time is attempting to understand how it could possibly be over two million years old. Running fingers along the edges reveals how sharp the tooth is, and with a triangular shape, it makes sense why smaller shark teeth made excellent projectile points for arrows. This specimen was a gift to our collection from a fellow fossil hunter and it certainly is an exciting addition.

Trying to figure out how common or rare big tooth shark fossils are can be a challenge. As the largest ancient shark even by conservative estimates, maximum sized megalodon had five rows of teeth with close to three hundred individual teeth filling the jaw in total. Multiply the number of teeth per animal by how many existed over a twenty million year period.

The anterior megalodon tooth pictured here measures 1.81 inches on length one, 1.56 inches on length two, and 1.38 inches wide, suggesting it resided deeper in the jaw of a conservative size or younger shark. Some of the largest anterior megalodon teeth are more than three times the size of this one, measuring upwards of six and seven inches on the greatest length.

Rock Layers

One defining characteristic of no-gem and non-precious rock jewelry and ornamental decoration which people are drawn to is the layers or patterns of material formed when the rock was created. Whether a repetitive pattern of symmetrical balance or an asymmetrical masterpiece, rock layers create their own sense of beauty and appeal. Varying color and material types compressed together in lines and swirls are elements of natural wonder in a rock hound world. It is not always about rarity or materialistic value, but instead it's about what mother nature is capable of creating to some. Agates and agate-like rocks are sought after by collectors by the beauty of polished layers it seems, even more so than perceived scarcity.

Scientifically, layers in specific kinds of rock are very important to determining past events on Earth. In those formations, sediment built up over many thousands of years, and the layers provide an accurate record of what was happening on the surface of the planet at that time; similar to reading the rings of a tree cross-section. For example, in areas near ancient volcano fallout, layers of ash which once blanketed the Earth's surface were buried in time. Analyzing the depth of an ash layer and its proximity to the volcano can tell scientists the scope of an eruption and provide information about environmental differences before and after the event took place.

Much of what we understand about the history of Earth in terms of age and past catastrophic events is by in part attributed to geology examining the formation of rocks and sediment layers. As a rock hound, finding rocks with distinctive layering is attractive on multiple levels. Firstly, there is the beauty of the rock itself from an artistic perspective, and then there is appreciation for natural processes and time required to create the rock. Although the example layered rocks shown are not precious metals or gems, they still retain intrinsic value to this rock hound as reminders of what nature is capable of creating by combining sediments and material.

Orthoceras Nautiloid

Related to modern day squid and octopus, the Orthoceras is an ancient cephalopod that lived in the Paleozoic Era, during the Ordovician period around 480 million years ago. Orthoceras fossils are quite abundant and a popular choice for necklaces, pendants, and decorations. This particular polished specimen was found at a local fossil emporium and caught our attention right away. Contrasting marbleized white shell and black stone emphasizes detail of the cephalopod structure which certainly catches the eye.

Additionally, the Nautilaidea Orthoceras is named for having a shell as straight as a horn, which is sometimes another attractive quality in jewelry design. It's understandable to see how one might see the suture lines as something similar to how an exotic plant stalk or leaf might fossilize, yet the narrowing tube shape displays a distinct three-dimensional tube especially when examining the thinnest portion. The black and white fossil has light marble features in the base rock that are likely fragments from other cephalopods fossilized at the time.

We hope the description of characteristics and features of the Orthoceras helps others identify this fossil in a collection. Holding onto an ancient rock that was once a creature living almost 500 million years ago is difficult to believe it's really so old, but to us this is part of the thrill and excitement hunting for fossils and learning about their origins in the timeline of Earth's history.

Raw Emerald

Mining in the United States for precious gems can be a fun and rewarding experience, especially when it comes to learning about mineral formations. One gemstone in particular, the emerald, is sought after for both rarity and beauty. The rare aspect is dual-fold, in that concentrations of emeralds are not very common, but also because finding facet-quality emeralds is even more rare. For example, the raw emerald specimen from North Carolina pictured here demonstrates how the formation can be a limiting factor in the size of emerald crystals.

Emeralds are a possible byproduct of hydrothermal processes when conditions and chemical composition are optimal. The way to envision this is to imagine hydrothermal fluids under extreme pressure being forced to the surface and pushed through rock cavities by water or magma. When the catalyst recedes, hydrothermal fluids are left in the rock cavities to cool and form emerald crystals. Emeralds created under these conditions in crevices and rock fractures, which means jagged fractures largely determine the size of emeralds formed.

Clarity is another factor in the rarity of emeralds. The deposits might be in proximity to calcite and other minerals which may cloud the hydrothermal fluid. This specimen demonstrates a ratio of clarity, where the majority of emerald crystal is foggy and opaque, while only a small fraction is clear enough to allow light to pass. Stripe patterns from internal crystal fractures are visible throughout the crystal material. Emerald can be surprisingly fragile and it's possible cracks in the crystal are the result of increased pressure or rapid cooling during the solidification phase.

The specimen also reveals how the shape of rock cavities and fractures play a role in the formation of emerald crystals. Edges of this crystal have been rounded and slightly polished to reduce further chipping or fracturing when handled as a demonstration piece. The monetary value of the specimen is quite low without a complete raw formation and the lack of sizeable pieces with clarity for faceting, but it is still a beautiful gemstone to have in the collection.

Raw Copper

While hiking along Lake Michigan's eastern shoreline, we happened upon a very interesting specimen of what appears to be raw copper complete with teal oxidation. The rock had tumbled up the beach from wave action and caught the eye almost immediately. Light bluish teal and copper colored flecks dot the outside of the rock on both sides. One side contains more areas of oxidation and larger pitted cavities where the copper meets the surface.

The opposite side features small pits with copper flecks shining through on its surface. Round, crater-like holes, likely from weathering erosion effectively cover this side. Dots of copper are found among these tiny craters. The surface also developed a bit of sheen from tumbling in the waves with smaller rocks. After searching the area thoroughly, no similar rocks, fragments, or gemstones were found in the vicinity.


Though copper isn't often sought after by rock hounds, it's still a great to add to a general collection. Plus there is a distinct possibility of locating precious gems in the same area as copper deposits. Interestingly enough, we did want to find a piece of copper in a natural setting, however a specimen washed up on the beach is some distance away from the concentration. In fact this rock could have been part of a payload crossing the lake at some point. Either way we are happy to include this specimen in our collection, possibly as a stone to slice open for further analysis in the future.

Montana Sapphires

The first time traveling through Montana was quite the experience on a number of levels. We definitely understand why it is often referred to as Big Sky Country and it did not disappoint. Our goal was to tour around, explore a little, and look for gemstones. Since we were first time travelers, sticking to areas where the public is welcome is a must. Brooks and streams which could contain gems are plentiful, but many reside on private land and require permission from the land owners.

After some research and driving around, we discovered Gem Mountain in Philipsburg, Montana. It's easy to feel whisked away from the rest of the world, a getaway in your own little mountain town, in the quaint town of Philipsburg. The stay here is refreshing, and motivational, knowing there's beautiful scenery all around you, and that you're only a short drive away from an active sapphire mine nestled in the mountains.

We spent an entire day panning through tailings brought down from Gem Mountain. By mid-morning we really had a handle on the techniques taught by mine operators and were finding sapphire after sapphire in the load. At the end of the day we extracted more than enough raw sapphires to cover the day's mining expenses. A decent portion of the raw could be cut for jewelry, and there were even a few nice flawless specimens. Firing and hardening can be done right at the mines for a fee, but we decided to keep the stones raw.


Overall, the experience panning for sapphires in Montana is one well worth the time and effort. In a way it's amazing to think some of these old gem mines are still producing significant amounts of raw material on a daily basis. As awesome and educational as panning through tailings is, the next trip calls for a more adventurous experience on our own, now that we have a pretty good idea of what to look for.

Sunstones in Sagebrush

Mining the barren countryside of Oregon is an enlightening experience and it definitely is interesting to prospect. For miles in all directions, flats of sagebrush and sand with seemingly random loose gravel roads jetting out into the landscape. When driving along the back country, Pronghorn Antelope in the area may run beside or gallop ahead on the pathway. Veering off the gravel roads are long, rough dirt side roads winding through the sagebrush on the way to areas of interest. One of these off-shoots took us to the Oregon Sunstone mining area. To get there and back safely, 4WD and patience is recommended.

For a while we had the feeling as if we're the only ones out there, and then we reached a quarry area. Not far from the public mining area were private claims with conveyors, trenchers, and mobile homes parked on the lots. In the public area, a single pit outhouse, parking area, and a small shelter. During several hours mining here, only one other visitor showed up. They didn't stick around for too long and left shortly after letting their dogs out.

By early afternoon we we're getting better at finding Sunstones and located several shallow pockets with dense concentrations near Sagebrush roots. Areas other visitors dug may be visible by looking for deeper depressions in the sand. It's also wise to keep an eye while digging for any wildlife in the area, such as snakes and lizards, which was definitely on our minds throughout the day knowing any help for injury is miles away and over some rough terrain too.


Sunstones were found scattered all over the quarry in varying sizes and shapes. Mining here has a slightly different physical toll than other locations. A telescoping sifter, or Sand Dipper, is helpful to reduce back pain. There's a lot of bending over or squatting to sift through and pluck stones out of the sands. The experience was very exciting and once we started finding decent amounts it felt like we couldn't look anywhere without seeing a Sunstone resting in the sand. For that reason, we do want to visit the Oregon Sunstone quarry again, and we'll be much better prepared for the next trip after everything learned from this one.

Fossilized Plant Matter

Rock hounding along beaches and shorelines can be very relaxing when the weather is beautiful, especially in areas where the waves push new rocks to the beach in large concentrations. These piles of stones are a treasure trove of history and it's easy to spend hours on end sifting through for interesting specimens. This is exactly the case from a trip to Lake Michigan. We spent hours walking along the Eastern shoreline looking to find what the lake might have to offer, and we were not disappointed.

Two notable specimens found, pictured side by side on different angles, are filled with ancient plant matter in fossilized form of very porous material. The dark rocks have several white bands embedded throughout with distinct features and pits that resemble leaves compressed together or balls of leafy organic matter collected together before frozen in time. We found many rocks similar in shape, density, and plant matter concentration. It's likely to be a common fossil for this area.

The third specimen features a different type of plant with a more preserved structure when compared to the first two. For the number of rocks scanned during the trip, this fossil proved to be far less common and perhaps even a rare find; The only one from an eight hour exploration. Detail in the rock appears to be fossilized shells at first glance, yet the node spacing has us thinking it is more likely a plant fossil. The splitting between elongated sections is frequent and creates a definite fan shape.


Other unidentified details are present in this specimen, as evident on the backside, which could possibly be additional bits of plant matter. Part of the fun is finding fossils and the other part is sharing the finds with others. It's not always easy to identify a specimen, so it's helpful to get input from fellow rock hounds, plus sharing excitement seems to make it that much more exciting!

Montana Pseudomorphs

The first time finding these peculiar looking minerals is certainly one to remember. Smooth-faced sides, precisely fine edges, and distinct geometrical shapes of pseudomorphs may look like something cut by a machine or tool. Yet this is a natural process of mineral substitution which can retain the cubic crystalline formation of the replaced mineral. Truth is, we really didn't know pseudomorphs were at all natural, so we enlisted the help of local experts to learn more.

Four pseudomorph specimens pictured here were found in Montana while prospecting for gems. Each one looks like limonite from iron oxide pyrite mineral substitution and apparently a quite common type of pseudomorph to find. The smooth sides were distinctly visible in the surrounding material, and the difference in density made it fairly easy for extraction, which we preferred the experts to handle while learning techniques.

Discovering geometric pseudomorphs taught us more about the diversity of mineral formation, how unique rocks are created through substitution or casting, and how voids in material can provide a housing for minerals to form within a rock. The conditions for the process need to be just right, but the occurrence of those conditions is somewhat common in the mineral world. Finding pseudomorphs also reinforces the idea to always look closely to examine details; To stay patiently diligent and nature will surprise us.

Idaho Lava Rocks

Traveling to Craters of the Moon National Monument in Idaho is a genuinely beautiful experience on a nice sunny day. The unique, almost barren looking landscape of ancient lava flows resembles scorched Earth from distant vantage points. We stopped several times for photos along the way and managed to find two interesting specimens close to the side of the road a few miles from the park boundary.

Seeing lava fields here for the first time is definitely a bit surreal on multiple levels. Vast and concentrated fields of burnt rock surround roadways on the way to the park and in some places on both sides of the road. This makes the naming of the monument aptly appropriate as the escarpment looks like something straight from the moon or another world. Given the distance away at the time, we believe the rocks found are likely tephra material ejected from the Great Rift during the area's last known eruption phase.

Each volcanic rock specimen is very porous, with one rock a little more dense than the other. The first example is very light pumice material and seems to resemble perforated wood grain upon close inspection. Char marks are visible on all sides and holding the volcanic rock is like holding a significant part of local history.

The second lava rock specimen is more dense than the first with much smaller pockets and features a well defined soot coating around the edges. It is a fraction of the size of the first though still with its own unique character. Comparing these two rocks tells two very different, yet similar, stories about how they were formed over 2000 years ago.

It's easily understood how common lava rocks in nature really are by the frequency of volcanic eruptions around the world over time and large amounts of ejecta spraying across the countryside during violent eruptions. There is another, more modern clue, which is the use of readily available lava rock for decorative landscaping purposes. The same stones endured a volcanic crucible, formed by fire, and cast into the air by one of nature's most powerful forces.

Nevada Petrified Wood

During a long, hot day mining for opals in the Nevada mountains, we managed to find two very nice specimens of petrified wood in a large pile of tailings. After a good four hours or so digging through  multiple feet of overburden in the opal wall, we took a break to sift through tailings while having a bite to eat. To our surprise, there were many interesting rocks we wanted to add to our collection, but it was the petrified wood which really put the age of the site into perspective.

Finding gemstones is exhilarating, no doubt, and finding ancient wood gives an entirely different type of feeling. Holding a gemstone dug from the Earth feels like discovering a fraction of timeless crystalline beauty. Holding a piece of petrified wood however, feels as though you're actually touching an ancient piece of  vegetation that once lived and breathed on the Earth's surface, a very different kind of beauty.  

The first specimen is a decent size, measures half a foot long, and contains a chalky white ash similar bands found around or near opal deposits in the wall. Although this specimen is old, petrified, and looks quite stable, it is actually very fragile to handle. Fragments of the wood broke off even when carefully transported. There's a possibility the ash deposit runs well into the wood, creating an unstable void, but we have refrained from prying the piece apart for a better view so far.


The, much smaller, second specimen possibly was petrified for a longer period of time. This one feels more like holding a stone than a piece of very old wood when compared to the first. Each end is smoothed-off and encrusted. A small dotted void runs nearly the entire width and resembles a series of cavities where tiny opals may have once been embedded.

On the opposite side of the second petrified wood specimen is a larger void with a little thicker crust covering the end. Both sides have darkened areas that look distinctly like char marks. This is exciting to us, not only holding part of a tree from a long time ago, but also one subjected to fire before becoming preserved in sandstone and clay.




The day's finds also included several small opals in early stage development though nothing for cutting or noteworthiness; Most were about an inch long by a quarter inch in diameter with fractures. Despite that, we still learned about the formation of opals and how to delicately follow white bands to deposits. Locating those bands certainly is a patient process even when vertical layers of sandstone are quickly and easily removed.

Iowa Keokuk Geodes

Digging on the countryside in Iowa for eight hours yielded nearly three pails of geodes ranging from tiny golf ball to baseball sized rocks pulled from damp shale layers. It didn't take too long to get through overburden and into pockets of preserved geodes like the calcite example shown here. Patience definitely came in handy while digging as we were told to watch carefully for fossil specimens rarely found between the layers. This trip didn't uncover any of those sought after plant and coral fossils, but we did manage to find many beautiful geodes embedded in the hillside.

Most of the geodes revealed sparkling white or clear calcite crystals when split apart with a hammer pick. A handful of specimens featured yellow, brown, and orange coloring in the calcite which certainly grabbed our attention. Two of the geodes contained rather dark brown dolomite crystalline structures mixed with calcite. Overall, many of the rocks were pretty easy to open along cracks and fault lines though a few did require the help of a short 10 pound sledge and rock chisel.

Helpful tools for excavating geode clusters from the shale include a small rock pick axe, entrenching shovel, rock chisel, pry bar, small sledge, buckets and one container with water on standby. A soil pipe cutter may prove helpful for opening the stubborn ones. Since digging to the geodes is not a physically intensive process, and with the precision required for removing layers without destroying a potential fossil specimen, smaller tools and patience worked best for us. The water container on standby is to keep any fossil finds moist as they're found to later control the drying process. Exposing the fossil to dry are for too long right away causes it to crumble apart.

The experience is very much worth time and effort involved in locating geode sites then spending a day digging. Seeing first hand how these beautiful crystalline rocks are formed in the natural environment is quite interesting as well, considering many of the clusters show geodes in various stages of formation from a small nickle-sized ball to much larger, much like a bunch of grapes if the grapes varied in size. The prospect of finding rare fossils along with the geodes was certainly intriguing, but the thrill for us was every time a cluster of geodes were found buried in the layers of shale.