Willow Creek Porcelain Jasper
Article written by : Philip Stephenson Tigeroakantiques.com 8/17/07
The intent of this article is to educate the public and not to discredit any individual or organization.

Willow Creek Jasper is one of finest porcelain jaspers in the world. Given the quality of material seen on the Internet, most collectors are not aware of the outstanding qualities of premium material.  Willow Creek jasper is mined 15 miles north of Eagle, Idaho. (NW of Boise, Idaho). The Jasper forms in the center of giant thunder eggs and rarely in seams. One of the prevailing theories, as far as Willow Creek goes, is that these thunder eggs formed deep within the earth, then were trusted up through large volcanic vents where they accumulated and solidified surrounded by very hard rhyolite.

Mining the Thunder eggs is very difficult hard rock mining. Dynamite is used to loosen the eggs within the rhyolite matrix and once loosened, next comes the back hoe and pry bar. Once free, the eggs may only be opened by sledgehammer and wedges.

Willow Creek Jasper is known for its subtle pastel colors, streamer patterns, and egg or orb patterns. Premium quality Willow Creek is unmatched.   It takes an extreme high gloss… like liquid glass. People who have worked Willow Creek say it has pastel colors and is somewhat soft and delicate in nature…perhaps, but top premium quality Willow has dramatic coloring, and incredible patterning.  I consider it the purest porcelain of the porcelain jaspers. The Willow Creek Mine has been producing jasper for the past 35+ years but unfortunately a good deal of low grade is sold on the internet market today.

High grading Willow Creek rough is a little tricky and should only be done by someone with experience with this material or by having the actual rough in your hands to inspect.  Low grade Willow is often times sold as “good quality” only to have iron pits and iron stains though the entire piece. The pits are actually tiny iron balls that when cut take on the pit look to them. Anyway, here’s a prime example: Notice the iron pitting and stains within the jasper. Example #1, Example #2, Example #3 . Cabochons with these iron pits are very unattractive and will undercut within the harder jasper surrounding it. Here’s a cabochon that looks more like Chicken Pox, it’s actually iron pits. Example #4.

Still, not all is lost if you happen to get “THE POX” in your rough Willow Creek pieces. Many times you can still work around these bad spots but of course you are limited in your choices of patterns, also there might be a hidden pit just under the surface. In slabs, you can get an idea if there might be a hidden pit by looking at the other side but most often the sellers on Ebay do not have a picture of other side. Example #5.  Rust on the other hand there’s no way around it…the area is unusable.

Compared to other fine jaspers, Willow Creek has fewer natural fractures (cracks made by Mother Nature) which makes it more desirable when trying to optimize material losses. The fractures that do exist are typically single fractures and not spidery. Although the area close to the impacts of the hammer normally gets pretty messed up, see this Ebay example: Example #6.  Single fractures result from the breaking and wedging open the large thunder eggs. Helpful hint: When trying to buy any rough or slab by a photo it’s always desirable to see the rough/slab item you are buying dry, verses wet. Wet will make any fracture or defect disappear. Here’s a very good example: I found this a few years back out on one of my rockhunting trips.  I got very excited about the orbs with the black jasper background. Wet Example #7, Dry Example #7.1. Now, it’s my wife’s favorite stepping stone in her garden. 

Now, see two examples of Willow Creek Porcelain Jasper at its most purest. These are now in my Willow Creek Collection. Example #8. Example #9

Buying unproven rough of any kind or finished pieces over the internet should undertaken with extreme caution. Only a few reputable dealers sell excellent Willow Creek Jasper on the Internet including finished pieces, and proven or unproven rough.


Below is a partial list of my reputable Dealers and Artists:





Ebay Name:

Gene Stewart



Neal Shornack



Terry Maple



Skye's Gems and Minerals



Sam Silver Hawk



Keith Hale



Neil Yeager



Gene Mueller



Astro Gallery of Gems



Dragon Madej