noun[mass noun] Geology
A dark hard film of oxides formed on exposed rock surfaces in arid regions.
More example sentences
- Many rocks in arid areas sport desert varnish, a dark, shiny coating rich in iron oxides and manganese oxide.
- Scientists have developed a quick, easy, portable, and nondestructive way to determine the age of desert varnish, the mysterious dark coating that slowly develops on rocks in many arid regions of the world.
- There are rocks formed in desert regions on the Earth, called desert varnish that form coatings by processes that are not well understood and at least some of these coatings look superficially like desert varnish.
Definition of desert varnish in:
- The US English dictionary