出典:Wiktionary
出典:Wikipedia
出典:『Wikipedia』 (2011/07/03 12:08 UTC 版)
Desert varnish, or rock varnish is a orange-yellow to black coating found on exposed rock surfaces in arid environments. Desert varnish is usually around one micrometer thick and present nanomater-scale layering . Rock rust and desert patina are other terms which are also used for the condition, but less often.