<p>Rock salt (halitite) from the Permian to Triassic to Austria (10.7 cm across at its widest).
</p><p>Evaporites are crystalline-textured, chemical sedimentary rocks that form by the evaporation of water (usually seawater) and the precipitation of dissolved minerals.  The most common types of evaporites are rock salt (halitite), rock gypsum (gyprock), and rock anhydrite.  The rock shown above is a halitite (rock salt), composed almost exclusively of the mineral halite (NaCl - sodium chloride).  It comes from a very old salt mine in the Halle-in-Tyrol area of Austria's Northern Calcareous Alps.  Many old salt mines occur along an ENE to WSW trend in these mountains.  They exploit the Haselgebirge Formation, a highly structurally deformed evaporitic sabkha deposit in an ancient failed rift of the Tethys Sea.
</p><p>Stratigraphy: Haselgebirge Formation, Upper Permian to Lower Triassic
</p><p>Locality: salt mine at or near Halle-in-Tyrol (Hall in Tirol) (possibly from an old salt mine at Absam in the Hall Valley, north of Hall &amp; east of Innsbruck), Northern Calcareous Alps, eastern Alps, North Tyrol, western Austria
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<hr><p>Mostly synthesized from:
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Leitner, C., F. Neubauer, R. Marschallinger, J. Genser &amp; M. Bernroider.  2013.  Origin of deformed halite hopper crystals, pseudomorphic anhydrite cubes and polyhalite in Alpine evaporites (Austria, Germany).  International Journal of Earth Sciences 102: 813-829.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a>
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<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/jsjgeology/15195697744/">Rock salt (halitite) (Haselgebirge Formation, Upper Permian to Lower Triassic; salt mine at or near Halle-in-Tyrol, Northern Calcareous Alps, western Austria)</a>