Our most important, and only spice with mineral origin is salt, more precisely table salt. It is either produced by distilling seawater or mined. Mined salt is called rock-salt, the scientific name of which is halite. It is sodium chloride chemically with the formula NaCl. Salt mining in and around Wieliczka, Poland, began in the 13th century. In the Middle Ages, during the reign of the Jagiellonians, one-third of the income of the Kingdom of Poland came from salt mining. Wieliczka still has salt production, but the salt is no longer mined but dissolved and evaporated using water. The tourist route, built in the deep salt mine at the turn of the 18th and 19th centuries, is still a popular destination for visitors.
In the picture: Halite (rock-salt), Wieliczka (Poland). Size: 12 cm. Photo by László Tóth