Love it when you share your rocks, I see many shapes in
these ones, like a buffalo on the top of the first photograph!Oh wow what wonderful boulders ❤ @melinda010100! :-)
This site says its desert varnish.
Thank you for sharing these beautiful boulders!
Ha! Now I clearly see the Buffalo, too! What an interesting article! Rock varnish. I've seen it often but assumed it was something leaching down from above.
Almost looks like a second buff behind the first! :-)
I had to go back and look again, but I think you are right!