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Moving On in a Desert Wash

While my book lies dead or dying, I continue to collect and learn. The world is too fascinating to continue mourning.

On Friday I collected from two desert washes near the colorful art installation called Seven Magic Mountains outside of Las Vegas.

This first photo shows mud cracks in stone. Slate or some such. Does not fizz readily under acid like the next rock.

This second photo is a poor example of limestone with a surface solution, collected that Friday just for illustration. Notice how much finer the lines are than the mud cracks, a closer knit group of spider webbing. Limestone with a surface solution is common throughout the Southwest. Keeps scrolling to see a reference specimen.

This third photo is a reference specimen of limestone with a surface solution. I bought it from professional geologist and former instructor R.C. de Mordaigle. He runs Geological Specimen Supply in Olancha, California. It’s the best place to start your reference collection of common and uncommon rocks. R.C. was a great supporter of my book.

R.C. explains these cracks in limestone this way, “In arid areas both limestone and dolomite develop a rough dissolved surface from the action of weak carbonic acid as atmospheric water picks up carbon dioxide . . . .”

What the collector really wants to find in wash are ripple marks, distinct marks in stone caused by wave action millions of years ago. This specimen is mudstone from somewhere outside Barstow, California. Look closely at the second photo. This isn’t just a piece of somewhat striped sandstone. Notice how it has real relief. Ripple marks.

Notice the relief in this second view.

I was on a Barstow area field trip one summer and saw a woman collect a nice ripple mark specimen from a desert wash. That arroyo had just been hit by a summer rain. Alas, I myself did not find a ripple mark but I did collect a nice piece of sandstone with dendrite markings. Another story for another day. Keep looking!

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My Apologies to the BLM

I wrote previously that the BLM doesn’t recognize rockhounding anymore as an activity. While that may be the case at the national level, the BLM in California still recognizes rockhounding as the vital and rewarding hobby that it is.

This page recognizes rockhounding with a video featuring Bill Depue, Founder and President of Diamond Pacific Tool in Barstow, perhaps the leading manufacturer  of lapidary equipment in the world. I had the great privilege of meeting Bill a month or two ago and I wrote about it here. In keeping with his modest character, Bill wears a Diamond Pacific hat but never mentions his involvement.

Interestingly, that page does not list all California BLM  rockhounding sites, it just mentions that the activity exists. Their Needles field office once had no reservation about describing sites.

Click here for an archived page that list sites under Needles’ management along with photographs showing what might be collected at each one. This is true endorsement. But I appreciate any effort that BLM California makes. Thank you!

Photograph below of Bill Depue.