Contemplation of a Constellation of Salt Crystals

Salt crystals floating on water in a sinkhole at the Dead Sea, Jordan. The Dead Sea is one of the saltiest water bodies on Earth. In a sinkhole within salt deposits adjacent the sea, intense evaporation leads to supersaturation of groundwater brine with respect to salt (esp. NaCl) and the precipitation of large (cm-scale) floating salt crystals. The more dense salt floats on the water due to a number of possible factors, such as the hypersaline water’s high density, its high surface tension, and the possible entrainment of gas in the crystals. In commercial salt production, such floating crystals are harvested and sold as a culinary speciality known as ‘Fleur de Sel’. These naturally-formed crystals disappeared overnight after a rare rain shower, highlighting the fine balance of environmental conditions at the Dead Sea.