In January before the Tucson 2020 show we decided to work a small exploratory dig at a private property in Southern AZ. We had been working with the land owners the past year, trying to open the property to more public access. During this time we had discovered a zone that was producing small clusters and individual Japan law twins. Some of these crystals were showing secondary if not primary amethyst, this peaked our interest.
The general region is an odd combination of folded Limestone, and granite and igneous intrusions. Where numerous skarn viens meet the limestone quartz, copper, tungsten and other mineralizations occur. Mining began as early as the late 1600’s by the Jesuits using forced Native labor to mine silver. Major silver mining occurred in the 1800S and copper in the late 1800s to the early 1900s.
As specimen collection grew in popularity this area was dug extensively for highly valued Japan law twins. Many great mineral specimens came out of this region from surface and underground exploration. Other notable minerals included amethyst quartz, andradite garnets and calcites.
DIGGING IS COMPLETELY OFF LIMITS IN THIS ARA.
Known for it’s Japan Law quartz twins this was once a classic Arizona location for rockhounds and serious miners alike. About twenty years ago a land developer bought these patented mining claims and created a large lot subdivision. As lots sold and a couple of the owners moved in the homeowner association decided to restrict diggers and prosecute trespassers. Since this time the only specimens to come out of this area have been surface collecting sometimes allowed by some of the land owners and small pockets taken out by trespassers technically Claim jumpers as these are patented mining claims.
We have been working with land owners in the area for years to allow us limited digs with their permission and supervision.
Our dig began In a scarn vien that runs from small mine to small mine. Digging next to me in the side of a small excavation from the old mine, Dano Fortunado an Arizona local and I had found a small but productive surface pocket. Many years previously I had found a zone of iron rich small twin clusters that displayed iridescence in this pit. This pocket however was more the classic twins from this locality with a secondary hazy quartz growth hiding the clear quartz underneath. With the nice twin clusters we found some amethyst rosettes. In the time between the owners of the property had let some Arizona diggers in that supposedly found several twin plates with some amethyst twins. This was encouraging enough for me to plan a return with a small machine and some help.
After working a machine on a trailer up and over the pass and to the area, we were ready to start work. Kiel Stroupe and Carey Williams had come to document the dig with videos, in the long run however they spent much of their time pulling crystals from the vent. We started by clearing the area of old tailing and medium sized scarn boulders. As we cleaned the area up we were confronted with small viens of crystalized quartz and small twins disappearing into huge boulders of hard green garnet. We hadn’t come prepared to drill and blast. As often seems to happen while scrapeing along these tight seems, one area under a formidable wall began to open up.
As the vein structure opened leading us under the boulder wall numerous small and medium twins and broken twins starting falling into our hands. Before to long we were plunging our hands under the wall into the loose decomposed skarn to pull out larger and larger clusters, most revealing twins. It was January 18th, Martin Luther King Jr. day.
From this stage we continued to widen our access into what was once a hydrothermal chimney. We carefully removed two huge plates of interwoven japan law twins. The two fit together making a plate over 2 1/2 feet long and 16+ inches across. As we later cleaned these plates we were a little disappointed to see pieces broken long ago and reattached with silica. The Plate had countless good twins but the earth had moved and changed it a bit much to make it the museum piece we originally hoped we had excavated.
We continued to works the zone from the bottom and top. some small rosettes of amethystine quartz were found, however all of the amethyst found seemed to be a secondary quartz. One piece in particular showed twins the a secondary amethyst and andradite crystals all together. We also found some interesting epimorphs of quartz after calcite and odd chalcedony balls.
All in all it was a successful dig. Although we again reached hard rock I am sure this vent continues further into the depths. We hope to approach this dig again with some different tools and ingenuity.