Desert varnish or rock varnish is an orange-yellow to black coating found on exposed rock surfaces in arid environments. Desert varnish is approximately one micrometer thick and exhibits nanometer-scale layering.[1] Rock rust and desert patina are other terms which are also used for the condition, but less often.
- ^ Krinsley, David; Dorn, Ronald; Tovey, N. K. (January 1995). "Nanometer-Scale Layering in Rock Varnish: Implications for Genesis and Paleoenvironmental Interpretation". The Journal of Geology. 103 (1): 106–113. Bibcode:1995JG....103..106K. doi:10.1086/629726. S2CID 129392419.