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Copper Canyon Pseudomorphs

Last Updated: 25th Aug 2014

By Rolf Luetcke

Copper Canyon Pseudomorphs
By Rolf Luetcke

The story begins with a short piece in Mineralogical Record magazine back in the 1990’s about a green pseudomorph of Malachite after the Calcite replacement clusters after Glauberite. The location they come from is in the Verde Valley of north-central Arizona. The deposit of the crystal clusters was well known for many years and there were three replacements of the original Glauberite found there. The very white Gypusm after Glauberite is delicate and good ones were hard to come by. The light brown Aragonite replacements often had crystals that can be seen under a microscope and these fluoresce slightly and phosphoresce. The most common replacements were the off white Calcite ones. They can all be found in single crystals to aesthetic clusters the size of one’s fist. Most have been washed from the host soil and the washing down canyon by rain and floods rounds most of the clusters so the edges are not crisp and sharp. At the place in the upper canyon where the crystals can be dug directly from the soil layers where they grew you find the best crystals. In this layer I found the Aragonite and Calcite but not the Gypsum. I am not really sure if they formed with the others or formed somewhere else but we never dug any in the soil layer. The only Gypsum ones we found were in the creek bed and had been badly worm by washing along with debris.
The green supposed Malachite pseudomorphs that appeared on the market were said to be colored by a copper mine in Copper Canyon. Supposed leaching of the copper salts invaded the beds where the crystals were and replaced them with Malachite. My parents lived in Sedona at the time and the Verde Valley was a short trip away. I asked if my folks knew where Copper Canyon was and they not only knew where it was but had been there. They loved day outings and with their jeep, took a trip to look for the beautiful green crystal clusters after we told them about how we had seen an article about them.
When I talked to them to see what they had found they said they looked all over the canyon and found only the light colored ones and not one green one. They also said there was not a mine in the area. I asked if they had any idea about the origin of the name copper canyon and they said it was because the canyon had a lot of deciduous trees that turned beautiful copper color in fall.
On our next trip up to visit my folks we took a side trip to Copper Canyon, which is right off of the freeway that goes between Phoenix and Flagstaff. The freeway descends into the Verde River Valley and it is just before you get to the the valley that Copper canyon is just off to the South. In fact you can see the canyon as you drive down the freeway into the Verde Valley. We found the area where the Calcite clusters were eroding out of the sides of the canyon walls and did some digging for the nicer sharp crystal clusters. We did find all three replacements of the original Glauberite, only the Gypsum was in the wash and not in the soil where we were digging. In the few hours we were in the canyon we picked up numerous beer flats of the crystal clusters.
When we returned home we decided to see if we could figure out how the people were making the fake specimens. The first attempt used Chalcanthite in a water solution and we put in the Calcite clusters. The Chalcanthite came from an old specimen from Bisbee that had mostly degraded to a bluish-white powder, which dissolved easily in water. It had been stored in a sealed jar but over time had degraded. While living in Bisbee I remember that after heavy rains the walls along the highway just below town turned blue with Chalcanthite that leached out of the soils. Tourists would chip the blue off the walls and pack it away in their luggage thinking it was Turquoise only to find it degraded to a powder when they got home and the wrapping eaten away by the acids in the material. My neighbor worked underground in the mines and one time brought me a six inch stalactite of the translucent blue Chalcanthite but that too quickly was degraded by the dry air outside of the mine. It was a spectacular specimen and I had wished it would have been stable.
After a day the clusters were coated in nice blue Chalcanthite crystals. Since we live where there are a lot of Gypsum “roses” we also tried the process with our Gypsum clusters but those also only grew the Chalcanthite on the outside. So that was not what people were using. The second attempt was using crushed copper ore with Malachite, Azurite and Chrysocolla in a solution of weak hydrochloric acid. The copper ore we used was a fragile assemblage we found in large quantities in Courtland Arizona and was perfect for crushing. After a day the white Calcite clusters were turning a nice green but were a bit light. The Calcite was porous enough to absorb the color nicely. After a second day in the solution the crystal clusters looked exactly like the ones that we had seen in the photos in the article. Now we knew how the people were coloring the crystals.
Sadly we proved to ourselves that the ones that had been selling as natural were in fact fakes. There was never a name attached to who was selling the fakes but today everyone knows that the crystals are not natural.
We have several friends who had these Malachite pseudomorphs in their collections and we told them that they were not natural. Sadly they had paid a hefty price for the specimens.
We tried the same process with the Aragonite clusters but those didn’t absorb the copper color as the Calcite ones did and we never did try the white Gypsum ones.
It is funny in a way that a canyon named for the color change of leaves in fall could lead someone to come up with a fraudulent scheme to make money by claiming that there was a copper mine in the canyon but that is what happened. Hopefully the ones reading this story are not among the ones that purchased one of the fake Malachite clusters.

Article has been viewed at least 4745 times.


Good story. Thanks for sharing. I not only loved reading about the history you provided but loved your "rock detective" work.

James Urbaniak
9th Sep 2014 2:46pm

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