Halite, the natural form of salt, is a very common and well-known mineral. It is found in solid masses, and as a dissolved solution in the oceans and in salt lakes. The inland lakes that are rich in salt exist in arid regions, and may also be below sea level without an outlet. These lakes evaporate during dry seasons, causing a recession in the water level and an increase of salinity content. When this happens, salt forms on the evaporated shores of the lake. This also happens as the tributaries of salt lakes are diverted for human and agricultural use, causing the lake to dry up with additional salt forming at the evaporating shoreline. Many of these inland lakes have already dried up, leaving over enormous salt deposits which may be commercially mined.

Halite also exists in non-arid regions, in underground deposits which can reach great depths. Underground Halite deposits are often mined by drilling wells into the salt layer, and bringing in hot water which quickly dissolves the salt into a brine. The brine is saturated with dissolved salt and is then pumped out. The brine evaporates and the remainder salt crystallizes and is harvested. Most commercially available Rock Salt is regrown from evaporated salt brine and is not the original natural crystals. Halite also forms from evaporation at salt springs where saline water comes out of the ground in a salt deposit and precipitates as rounded globular masses.

In some underground salt deposits such as Texas and Louisiana, salt is pushed upwards by an underground force through soft ground and forms arched structures known as salt domes. These deposits are also important sources of salt mining operations and are very unique geological formations.

Although the color range of Halite can be caused by impurities, the deep blue and violet colors are actually caused by defects within the crystal lattice, and the pink and peach colors of many dry lake Halite specimens are caused by bacteria from various algae.

Artificial Halite can easily be grown as crystals by allowing a saturated saltwater solution to evaporate. Hopper-shaped cubes may result as the brine evaporates and the crystal grows. A few Halite specimens on the market are actually artificially grown crystals formed in this manner.