<p>Dead Sea rock salt (halitite) (4.1 cm across)
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<hr><p>This is a friable mass of rock salt (halitite) from the modern seafloor of the Dead Sea in Israel.  The Dead Sea has the highest-salinity surface water anywhere on Earth (~30% or more total salt; ordinary seawater is 3.5% salt).  Dead Sea water has high concentrations of Cl, Mg, Na, Ca, and K.
</p><p>The Dead Sea is located deep in a tectonic rift valley, part of a rift system that extends south into the Red Sea and toward the Afar Hotspot.  Salt has accumulated in the Dead Sea because the lake lacks an outlet.  The only significant inlet is the Jordan River.  The Dead Sea is apparently devoid of life (hence the name “dead”), but it does have some halotolerant/halophilic bacteria and algae.
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This rock is composed of halite (NaCl - sodium chloride), the most common mineral that precipitates from Dead Sea brine.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a>
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/jsjgeology/14851324697/">Rock salt (halitite) (Holocene; seafloor of the Dead Sea, Israel) 1</a>