Rock salt crystals can attain a remarkable size. However, specimens weighing a thousand kilograms with cubes up to 30 centimeters long are an absolute rarity.
A THOUSAND KILOGRAMS
The largest salt mine in the Austro-Hungarian Monarchy was located in Wieliczka. The deposit is ten kilometers in length and up to 400 meters thick in places. It was laid down during the Miocene period, 23 to 5 million years ago, when a particularly warm, dry climate caused a sea to evaporate. Even in the Neolithic Age 3,500 years ago, Wieliczka was already a center of salt production – white salt was obtained by evaporating brine in large pans. Around 1900 a labor force of more than 1,500 men mined up to 50,000 tons of salt a year, a quarter of which was used as table salt. By the 19th century, Wieliczka had an extremely professionally organized show mine complete with cloakrooms and sales booths. The program included various guided tours with background music, colorful lighting effects, and even flares and pinwheels. A report compiled by the mine administrator in 1896 “in consideration of outside visitors” reveals that the mine was enormously popular: “More than 400 persons are not admitted. It is not necessary for visitors to push and shove, as everyone sees the same things.” Today the extensive underground facility is part of the UNESCO world cultural heritage and is still a tourist attraction. The Austrian painter Hugo Charlemont was sent to Galicia in order to sketch the mine for a wall painting for the mineralogical collection of the NHM (Hall I). In return, the imperial and royal Ministry of Finance donated this magnificent rock salt crystal to the museum and had it transported from Wieliczka to Vienna in the year 1900.