The Pacific Northwest is a beautiful area, but just underneath the soil also lies a collection of beautiful rocks, gems, and minerals ranging from elemental gold to green petrified wood. Most people in the region know there are some good rocks around, but it’s always a matter of being able to find them.
So, let’s take a big look at some of the hits from across the region with our list of rocks and minerals found in the Pacific Northwest.
Rocks and Minerals Found in The Pacific Northwest
1. Oregon Sunstone
Oregon Sunstone is a plagioclase feldspar variant. While ordinary sunstone occurs in large masses, Oregon Sunstone is generally found as large single crystals. These crystals have a wide variance in color, but they all share a schiller effect similar to labradorite. The end result is a world-class gem, always found in one part of Oregon.
The schiller is caused by elemental copper distributed through the crystals. Like other feldspars, Oregon Sunstone has perfect cleavage. This means it’s not a suitable gemstone for everyday wear for rings and bracelets, but it is hard enough to be used in other pieces of jewelry. Unsurprisingly it’s been the state gemstone of Oregon for a long time.
Oregon Sunstone isn’t found in many locations, it’s unique to the state. They often have color zoning in the same crystal, making for multi-colored displays. Even better, some of these stones are also color changing, depending on the orientation of the light entering the crystal. These crystals are cut by some of the best, including artists like John Dyer.
Due to their high value, the majority of claims are private and jealously guarded. Fortunately for the public, however, the Oregon Sunstone Public Collection Area is open to would-be prospectors.
Read More: Sunstone Mines In Oregon Open To The Public
Obsidian is technically not a mineral, since it lacks any sort of internal crystalline structure. Instead, the famous black rock is a glass. The properties of obsidian lend it well to being a cutting tool, namely the clean conchoidal flakes that break off when it’s struck. These flakes can have incredibly thin edges, for a brief time obsidian can make a razor look dull.
Obsidian is generally a dark rock, after all the name is also used to describe glossy black. It can also come in varieties with different sheens, such as Gold Sheen. There are also patterned obsidian types, such as snowflake obsidian and it’s chrysolite starbursts. And, of course, the famous Rainbow Obsidian is native to the Pacific Northwest… if you can find it.
Past volcanic activity has made much of the Pacific Northwest home to the stone. It can be found in large pieces and several large formations are made entirely of obsidian. It’s an incredible rock, with a history of use by humans. The best prehistoric lithic tools were created using obsidian. People who knap know why, nothing flakes cleaner than obsidian with the exception of man-made glass.
Obsidian is found across the region, but it’s not allowed to collect it in some places. Instead, you may want to simply try heading out to Glass Butte, which hosts a wide array of different varieties and allows public collection.
3. Petrified Wood
Petrified wood is found in many places, but the colors and type depend on the locality. For the most part, petrified wood ends up being a brown or red color and is sometimes found as an entire limb cast. The minerals contained inside are usually opal or chalcedony, or a combination of the two. Different impurities in the ancient silica-bearing waters can lead to some striking results, however.
In this case, we have a lot of different colors but most aren’t all that striking. What is striking is the green-colored petrified wood colored by trace amounts of iron and copper. This wood ranges from a dark teal to a bright green and there are even blue varieties that occasionally show up. It’s one of the wonders of the natural world.
That’s not to put down the incredible variety of different petrified wood found in the Pacific Northwest. Large limb casts are found in some locations and smaller pieces are strewn throughout the waterways. These smaller pieces are harder to recognize without their distinctive wood shape, but grain often remains in the patterns.
If you’re looking for petrified wood, then you’ll want to visit Hampton Buttes. Here the BLM manages a rockhounding area that’s open to the public.
Jade is present across this entire area, and even a bit south. Jade was once used as a simple descriptor for any stone that was green and could be worked, but nowadays it refers to two members of the pyroxene series. These are nephrite and jadeite respectively. Jadeite is incredibly rare, most jade found in this area is nephrite.
Then it gets complicated. The so-called Oregon Jade, for instance, is actually a green jasper. That doesn’t mean all jade from Oregon is jasper, there’s plenty of nephrite hiding around the region, but it points to the difficulty in identifying these stones. Being able to tell them apart is important, Oregon “Jade” is pretty, carves well, and takes a great polish but it’s a totally different stone than nephrite jade. Nephrite can also come in many different colors, making it harder to identify.
The easiest way to tell these two apart is to run tests for their specific gravity. Jasper is less dense, at 2.5-2.9 while nephrite is usually a bit higher at 2.95-3.05 depending on the various impurities. If you run this test on jadeite you’ll end up with a higher number at ~3.4. A simple test can end all arguments about the identity of your stone.
Nephrite jade can be found on the Pacific Coast beaches, while jadeite can be found around Whidbey Island. There are other places spread throughout the area as well, just remember that not all jade is green!
Opal is an amorphous form of silica, comprised of microscopic spheres stacked in complex arrangements. It comes in two main varieties, precious and common. Precious opal is what most people think of when they hear the word, with a scintillating internal fire that changes as the stone is turned. Common opal is generally less impressive, lacking fire but sometimes showing great color patterns.
Precious opal is a rarity, with only a few of the many places that produce opal having that fire. In the US there are only a few locations that bear it, but several of them fall in this region. Precious opal is known from both Washington and Oregon, as well as Idaho. It’s rarest in Washington, but the state also shows a surprising array of different types.
Finding precious opal is hard, even when you have access to the right areas. The high value of precious opal has made it a hit for most of human history… and that means people have laid claim to most of the better spots. While some locations offer paid digs, most aren’t open to the public in any way. Fortunately, there are a few spots you can check without having to try and talk someone into letting you on their mining site.
In Idaho, your best bet is to try a paid dig at the Spencer Opal Mine. Meanwhile, the Juniper Ridge Opal Mine in Oregon offers paid digs for fire opals. Washington tends to bear opal along the coast but lacks any paid dig sites.
Read More: Ultimate Guide To Collecting Opal
Quartz is the macrocrystalline form of silica, made up of six-sided crystals with a pyramidal termination. This iconic crystal has long left the hands of only those who collect stones and the crystal points are a common find in all sorts of shops, not just those that sell rocks. Quartz has fascinated humanity since ancient times. It must have been a truly odd material to find in the time before glass was common.
Amethyst is also a variety of quartz. In this case, it appears that the coloration comes from iron located in the color centers of crystals. While quartz has long been prized, amethyst has actually become devalued in the last few centuries. Previously only a few small deposits bore the purple gemstone and it was considered the equal of ruby and emerald. The discovery of the massive basalt fields in Brazil, and the huge amounts of amethyst contained within, lowered the value a touch.
Quartz and amethyst are often found in the same locations. While neither is uncommon in the United States, the quality of the stone varies from place to place. The three states classically associated with the Pacific Northwest all bear some varieties of quartz. Idaho bears mainly smoky quartz, while amethyst and clear crystals are more common in Washington and Oregon.
Boise County in Idaho is known to house some stunning specimens of smoky quartz, while amethyst can be found east of Seattle in Washington. Meanwhile, there are hundreds of locations found in Oregon for the potential crystal hunter.
Read More: Ultimate Guide To Collecting Quartz
Agate, jasper, and chalcedony are all intimately intertwined minerals. All three are a form of chalcedony, which is a complex intergrowth of quartz and moganite on a microscopic level. At our scale, these stones often seem waxy and smooth, as opposed to the more granular edges found on larger crystals. All three are common finds in the United States, and some of the more amazing varieties can be found in this region.
While people like to argue about which is which, I much prefer collecting them. In many places in the USA all you need to do is head to a local stream or creek bed, dry or wet, and start looking. Still, not all varieties are equal and some locations simply produce prettier samples than others.
Some of the more famous stones in this category come from this location. Hampton Butte is known for producing incredible agates, while the Owyhee Mountain area produces the world famous Owyhee Jasper. High-grade carnelian agate can be found along the coast of Washington for those with an eye for the red stone.
There is no exhaustive list of the jaspers and agates of this region. For a beginner the best bet is checking along the coastline in rocky areas in Washington and Oregon, but searching stream beds is a sure thing in the area as well.
Thundereggs are generally a form of chalcedony but have long been considered their own thing. They take the form of a rounded nodule of stone, which display brilliant patterns and colors when they’ve been cut into. Thundereggs vary a lot, depending on the way they formed in the past. Distinctive varieties are prized.
A thunderegg differs from a geode. Geodes are largely hollow, with macro-crystals growing on the interior. They’re generally formed from quartz or calcite. On the other hand, thundereggs are solid, although many will have some small vugs contained within. It makes them a little bit harder to identify since they’re often heavier than the surrounding rock and lack the distinctive hollow ring of a geode when struck.
In Washington and Oregon these generally take the form of blue chalcedony contained within a reddish matrix. There are also waterline agates found in this kind of formation. In Idaho, on the other hand, one can find spectacular pink opal thundereggs along with jasper eggs from Bruneau Canyon.
Oregon is best known for eggs located in the Ochoco National Forest, but they’re spread across the central and eastern portions of the state. In Idaho, the spectacular opal eggs are found around the Spencer Opal Mine and can be found during paid digs.
Read More: All About Thundereggs And Where To Find Them
9. Placer Gold
Placer gold is a secondary deposit of gold found in the wake of erosion over time. Much of the gold in the world is locked into things like quartz, often in remote locations, which makes it hard to mine. Placer gold is the result of the erosion of these veins, often found as small flakes and tiny nuggets in creeks and streams across the world.
If you’ve ever seen anyone panning for gold, then you know what placer gold is. This secondary deposit is often found in sands and gravels in areas downstream from gold deposits. In the past it was an important part of finding larger amounts of gold, but most prospectors these days are hobbyists. Gold has been fought over since the beginning of human history, and most of the easily accessed hard rock deposits are long gone.
In most of the Pacific States there’s a surprising amount of different locations to find it, with some richer than others. If you do get lucky and find a nugget then you’re in luck: nuggets are often worth more in their natural form than as gold scrap despite their lower purity. The majority of this form of gold is 75-80% in purity, the gold having been mixed in with other elements in the past.
These days, your best bet is probably the Skagit River in Skagit County, Washington. But don’t let that stop you from dipping a pan in any stream that looks promising! It just takes a couple of flakes or grains to turn a lukewarm prospector into someone with a real interest!