English: Halite from the uppermost Holocene of Utah, USA. (the cluster at left is ~2.1 centimeters across at it widest)

A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5500 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.

The halides are the "salt minerals", and have one or more of the following anions: Cl-, F-, I-, Br-.

Halite is true salt, which consists of sodium chloride (NaCl). This is the same chemical long used as flavoring on food & as a preservative. It has a nonmetallic luster, typically clearish/coloress, and is relatively soft (H = 2.5). Halite forms cubic crystals and has cubic cleavage (= 3 cleavage planes meeting at 90º angles). Halite is most readily identified by its strongly salty taste.

Halite has economic value. In addition to its use in food, salt is traditionally used in large quantities in wintertime to prevent roadways from icing up. Halite is principally mined from ancient rock salt successions. Rock salt is a chemical sedimentary rock composed of halite and formed by evaporation of seawater.

Seen here are halite clusters from Utah's famous Great Salt Lake Desert. The water in Great Salt Lake is a brine - it ranges from 5 to 27% salinity. Average seawater is 3.5% salinity. When water in any portion of the Great Salt Lake basin evaporates, new halite forms.

Locality: Great Salt Lake Desert / Bonneville Salt Flats, west of Great Salt Lake, Interstate 80 rest stop, east of Wendover & west of Salt Lake City, northwestern Utah, USA

---

Photo gallery of halite: www.mindat.org/gallery.php?min=1804

---

See info. at:

en.wikipedia.org/wiki/Great_Salt_Lake