Rock Salt

Halite  Commonly Known As Rock Salt, Is A Type Of Salt, The Mineral Form Of Sodium Chloride (Nacl). Halite Forms Isometric Crystals. The Mineral Is Typically Colorless Or White, But May Also Be Light Blue, Dark Blue, Purple, Pink, Red, Orange, Yellow Or Gray Depending On The Amount And Type Of Impurities. It Commonly Occurs With Other Evaporite Deposit Minerals Such As Several Of The Sulfates, Halides, And Borates.

Halite Occurs In Vast Beds Of Sedimentary Evaporite Minerals That Result From The Drying Up Of Enclosed Lakes, Playas, And Seas. Salt Beds May Be Hundreds Of Meters Thick And Underlie Broad Areas. In The United States And Canada Extensive Underground Beds Extend From The Appalachian Basin Of Western New York Through Parts Of Ontario And Under Much Of The Michigan Basin. Other Deposits Are In Ohio, Kansas, New Mexico, Nova Scotia And Saskatchewan. The Khewra Salt Mine Is A Massive Deposit Of Halite Near Islamabad, Pakistan. In The United Kingdom There Are Three Mines; The Largest Of These Is At Winsford In Cheshire Producing On Average A Million Tonnes Per Year.

Unusual, Purple, Fibrous Vein Filling Halite Is Found In France And A Few Other Localities. Halite Crystals Termed Hopper Crystals Appear To Be “Skeletons” Of The Typical Cubes, With The Edges Present And Stairstep Depressions On, Or Rather In, Each Crystal Face. In A Rapidly Crystallizing Environment, The Edges Of The Cubes Simply Grow Faster Than The Centers. Halite Crystals Form Very Quickly In Some Rapidly Evaporating Lakes Resulting In Modern Artifacts With A Coating Or Encrustation Of Halite Crystals. Halite Flowers Are Rare Stalactites Of Curling Fibers Of Halite That Are Found In Certain Arid Caves Of Australia’s Nullarbor Plain. Halite Stalactites And Encrustations Are Also Reported In The Quincy Native Copper Mine Of Hancock, Michigan.