Mirabilite

 ( Sodium Minerals ) 

Mirabilite, also known as Glauber's salt, is a hydrous sodium sulfate sulfate mineral with the chemical formula Na₂SO₄·10H₂O. It is a vitreous, colorless to white monoclinic mineral that forms as an evaporite from sodium sulfate-bearing . It is found around saline springs and along saline . Associated minerals include gypsum, halite, thenardite, trona, glauberite, and epsomite.

Mirabilite is unstable and quickly dehydrates in dry air, the prismatic crystals turning into a white powder, thenardite (Na₂SO₄). In turn, thenardite can also absorb water and converts to mirabilite.

Mirabilite is used as a purgative and anti-inflammatory remedy in the Traditional Chinese medicine; in Mandarin, it is called máng xiāo 硭硝. The name 'mirabilite' is based on the phrase "Sal mirabilis" (Latin for "wonderful salt") used by Johann Rudolph Glauber when he inadvertently synthesized mirabilite.

Mirabilite is found in several areas within the Mammoth Cave System, where it appears to have been mined by Late Archaic and Early Woodland peoples, probably for use as a laxative.

Four mirabilite mounds were documented on the south shore of the Great Salt Lake, Utah, United States, in January 2020. These developed where springs surfaced along the beach, which had been exposed due to lower lake elevations, and cold air helped preserve the salt precipitate. This was documented by the Utah Geological Survey Mirabilite spring mounds mapped by the Utah Geological Survey at Great Salt Lake. as well as reported in the press. KUTV News: Rare salt formations appear along the great salt lake.

• Maricopa.edu
• American Mineralogist (1917)
• "Mirabilite as a tracer of past evolution of the Aral Sea"