Halite, also known as rock salt, is the mineral that is used as table salt and sea salt. It is formed as deposits that are leftover from evaporated seawater.
This specimen includes six pieces that are identified from left to right and top to bottom:
Red Rock Salt, White Rock Salt, & Yellow Rock Salt
Grey Rock Salt, Dark Red Rock Salt, & Gypsum
These specimens come from the Salzbergwerk Berchtesgaden Mine in Germany, which has been in continuous operation since 1517. The salt does not occur in its pure form, but is part of a composite rock and is extracted using a wet mining process. Fresh water is pumped into the rock to dissolve out the water-soluble components of the rock, creating a brine, which is then extracted and processed into industrial salt.