Desert Varnish

Desert varnish or rock varnish is an orange-yellow to black coating found on exposed rock surfaces in arid environments. Desert varnish is usually around one micron thick and present nanometre-scale layering. Rock rust and desert patina are other terms which are also used for the condition, but less often.

Read more about Desert Varnish:  Formation, Composition

Famous quotes containing the words desert and/or varnish:

    Full many a gem of purest ray serene,
    The dark unfathom’d caves of ocean bear:
    Full many a flower is born to blush unseen,
    And waste its sweetness on the desert air.
    Thomas Gray (1716–1771)

    People are less self-conscious in the intimacy of family life and during the anxiety of a great sorrow. The dazzling varnish of an extreme politeness is then less in evidence, and the true qualities of the heart regain their proper proportions.
    Stendhal [Marie Henri Beyle] (1783–1842)