The name is derived from Greek “hals” meaning salt.
Halite, also known as a rock salt is a water soluble mineral with a formula NaCl. Halite was the first mineral ever to be structurally studied by W. H. Bragg  back in 1912. It crystallizes in isometric system and forms well shaped cubic crystals. Octahedrally shaped crystals are less common. Rarely it is found in a form of stalactites and stalagmites . The structure of halite can be described as a close packing of Cl–. All the octahedral sites are occupied by Na+. Each Cl– ion is surrounded by six Na+ and vice versa. 6:6 coordination is thus observed in structure . It occurs typically in sedimentary rocks of evaporic association along with other water-soluble sulfates, halides and borates. Halite is usually colorless but blue halite has been found in the North America and in the Zechstein, Germany. This coloration is caused by gama-bombardement by associated potassium-40 found in sylvite or as written – followed by structure deformation .
Halite – unit cell 
Halite crystals, Wieliczka mine, Wieliczka, Malopolskie, Poland [photo: Michal Hegedus]
 Bragg, W. H., & Bragg, W. L. (1915). X rays and crystal structure. London: G. Bell.
 Spiroff, K. (1937). AN UNUSUAL OCCURRENCE OF HALITE. Mineralogical Society of America, 22, 931-933. Retrieved May 24, 2016, from http://www.minsocam.org/MSA/collectors_corner/arc/mihalite.htm
 Kutty, T. R., & Tareen, J. A. (2001). Fundamentals of crystal chemistry. Universities press.
 Zelek, S. M., Stadnicka, K. M., Tobola, T., & Natkaniec-Nowak, L. (2014). Lattice deformation of blue halite from Zechstein evaporite basin: Kłodawa Salt Mine, Central Poland. Mineralogy and Petrology, 108(5), 619-631. doi:10.1007/s00710-014-0323-9
 Walker, D., Verma, P. K., Cranswick, L. M., & Jones, R. L. (2004). Halite-sylvite thermoelasticity. American Mineralogist, 89, 204-210. Retrieved May 24, 2016.