Jasper is a beautiful stone, and the variation is enough to make any collector excited. When you’re diving into the world of rock collecting, they’re a great start.
For the beginning jasper collector, there are a lot of questions. Fortunately, there are also easy answers!
Let’s dive in and we’ll teach you what jasper is, where you can find it, and even give you some tips to make your next collecting trip a success!
What is Jasper?
Jasper is a form of cryptocrystalline silicon dioxide(SiO₂ or silica) that’s opaque. Jasper is usually characterized by bright colors, including green, red, blue, and many others.
Jasper is distinct from agate due to its opacity. A true jasper blocks all light, although some brecciated jaspers will have pockets of chalcedony in them. Generally, the stone will have some kind of pattern as well, even if it’s within a single hue.
Jaspers exist on a continuum of cryptocrystalline quartz. While they’re made of the same stuff as regular quartz crystals, the crystal structure is entirely different. The crystals in a cryptocrystalline stone are hard to find even with a microscope.
Jasper’s deep colors and opacity stem from impurities in the silica.
Jasper is an igneous rock but it often occurs in larger formations than agate. Jasper nodules can often be found in riverbeds anywhere near ancient volcanic activity. They’re surprisingly common in many parts of the United States.
What Types of Jasper Are There?
Jaspers, like agates, have a loose classification system based on how their surface patterns emerge. Some varieties also have their own names and specific colors.
Some of the commonly used names for jasper varieties are:
Imperial Jasper is a green form of jasper that is considered one of the rarest. In the modern market there are a lot of composites under the same name, be sure of what you’re buying!
Brecciated jasper nodules are broken up internally and cemented with chalcedony. The most common forms are cemented with grey chalcedony between red and yellow jasper but there is a multitude of different colors available.
Landscape Jasper are Earth-toned jaspers which display a “landscape” when cut. These often form the illusion of rolling hills, mountains, and other idyllic landscapes.
Poppy Jasper is a jasper with frequent small “blooms” across the surface, distinct from Orbicular Jasper which has solid orbs of color that show up as “eyes” when a slab has been cut.
Ocean Jasper is an orbicular jasper that occurs in Madagascar. It’s not named for its colors(which vary across the spectrum from blue to green to red) but instead for the fact that the deposits are often marine and only accessible at low tide.
That’s just a small sample of the offerings out there. Many jasper patterns have distinct names, and other jaspers are called for their place of origin.
There are also quite a few stones called jasper in their common name that consist of different minerals than true jasper. One of the most famous is Dalmation Jasper, which is a microcrystalline silica stone instead of a cryptocrystalline stone. Bumblebee Jasper also falls into this category, it’s actually a calcite mineral colored with pyrite, arsenic, and sulfur.
There’s an endless variety of jasper out there, and each stone produces its own unique pattern. It’s no wonder that the stuff is a favorite of collectors.
Buyer Beware: Fake Jaspers
Imperial Jasper is a pricey stone, so there are quite a few artificial substitutes out there. They’re not always clearly labeled, but if the price is too good to be true then… well, you’re probably not getting a good deal.
Testing is usually easy, most will burn readily if you apply a hot nail or needle to the stone. If it burns… well, it’s not jasper.
Most other jasper group stones aren’t fake, they occur in large enough deposits that it’s not profitable to create fakes.
Where Can I Find Jasper?
Jasper, like agate, can be found in most places that formerly had volcanic activity. Jasper varies a lot in appearance, however, and the variety in your own backyard may not be what you’re looking for.
In the United States, it’s common, but the most sought after varieties come from the following states:
Jaspers often occur in considerable quantities, so finding specimens of most types is easy.
You’re not out of luck if your home state isn’t listed above. Prospecting for jasper can be done very casually, and you may find some striking local varieties.
Search online for areas near you that may have jasper. It’s a lot easier to find them initially if you know what you’re looking for.
On that note, Google can be tricky when you’re looking for specific areas. I’ve found that going through different sources provides good information. For instance, you can find club field guides that provide a realistic overview of most areas.
Scouting areas with Google Maps can often help. The satellites aren’t perfect, but you can sometimes see large color changes on the ground and it never hurts to know how to get around.
How Do I Find Jasper in the Field?
Walking riverbeds is the best way to find jasper nodules in an area. Riverbeds collect stones over time, and dry ones are a treasure trove. Once you begin to learn how stones collect in the area, you’ll be able to quickly find areas that are likely sources.
You’ll want to bring the following:
- Water- For both drinking and to reveal colors on dusty stones. Make sure you have enough for the day.
- Rock Pick- Invaluable tool when prospecting. Useful for both hitting rocks and prying interesting specimens out of the ground. Wear safety glasses when using your pick to break stones.
- Pocket Knife- Use it for hardness testing and the usual hiking tasks. A stout knife can also pry stones out of the ground if you don’t have a rock pick.
- Eye Protection- ANSI-rated glasses are best, but make sure you have at least a sturdy pair of sunglasses on. Breaking rocks can be very unpredictable.
- Sturdy Bag- Unless you’re very selective, you’ll usually have quite a few specimens to bring back. Bring a bag that’s extra sturdy, jasper is very dense and the weight can rip cheap stitching.
Running streams are also a good place, especially since the stones are pre-washed. In streams, you’ll be looking for bright colors, but don’t be afraid to dig a bit if an area looks promising.
As always, knowing the local rock is key. The general bedrock isn’t what you’re looking for, so get familiar with its details and coloration. Jasper nodules and chunks are often large enough to be recognized from a good distance.
If you’re cutting the stones, large chunks are usually more appealing. Often these large chunks have striking patterns on the interior, even if they looked quite dull on the outside.
Identifying which stones are jaspers is easy in most cases. They’ll have a waxy feeling on the exterior, and often colored chunks will show on the exterior of the stone. This is the case in most riverbeds since larger stones have been broken down in the currents.
You can take off a piece of the “rind” of a jasper chunk with a rock hammer or hard cobblestone.
With your hammer, you’ll want to aim to use a corner of the square face. You’re trying to separate a conchoidal flake from the interior of the stone, which is one way to identify if you’ve got a chunk of jasper in your hands.
A conchoidal flake will have a rippled texture and they’re often quite thin. They’ll widen from the point of impact. It can be challenging to break one off properly, but most softer stones will just crumble in your hands.
Harder stones generally won’t break, but they’ll crumble if they do instead of creating a fracture.
Where you hit is also important, you’re looking for a protruding area that’s below the centerline of the stone. Try to hit on the very tip for your best chance at a flake.
If you have exposed stone that you think is jasper you test its hardness. A pocket knife will scratch most look-alike stones since they’re softer.
If you’re not cutting the stones you may want to take a different approach to gather them. Smaller pieces of jasper that occur alongside larger stones often display more color. Jasper can often display a smooth surface when found, so specimen pieces are usually picked for their exterior coloration.
These same stones can be tumbled if that’s how you prefer your collection.
For those cutting… expect surprises. They’re usually good, where you end up with a strikingly different nodule. Occasionally a stone that looked promising turns out to be a solid-colored dud as well, unfortunately.
Jasper is among the easier stones to collect on your own. It occurs across a wide part of the country and large chunks of it abound.
It’s no big task to find a spot to check, and the best experience is always gained in the field.