Rare blue Halite xl (classic locale)

Item Description

Shocking, rich, "electric-blue" color-zoning with waxy luster in an otherwise translucent crystal on this beautiful and rare blue halite crystal from this classic locale. This is rare older material from the Soviet era and is seldom available. This striking piece is in good shape. The two frontal faces and termination appear to be pristine. The two back out-of-sight faces are cleaved. From the Cal Tech website http://minerals.caltech.edu: Blue halite is the result of exposure to natural radiation. Initially, if halite (common salt) is exposed to gamma radiation, it turns amber because of F-centers. They are mostly electrons trapped at sites of missing Cl- ions. In time the electrons migrate to Na+ ions and reduce it to Na metal. Atoms of Na metal, in turn, migrate to form colloidal sized aggregates of sodium metal. They are the cause of the blue color. An excellent crystal valued at $400-600.