Tachyhydrite
Deliquescent calcium and magnesium chloride mineral
Tachyhydrite is an unstable mineral, a hydrous chloride of calcium and magnesium with formula: Ca Mg2Cl6·12H2O. It is a rare component of marine evaporite salt deposits. Upon exposure to moist air it rapidly deliquesces and dissolves.
It forms a colorless to yellow trigonal crystal with a vitreous luster. It is soft with a Mohs hardness of 2 and has a low specific gravity of 1.66. It has good cleavage in three directions and typically occurs in crystalline masses.
It was first described in 1856 for an occurrence in Stassfurt, Saxony, Germany. Its name is from the Greek for quick water, in reference to its ready deliquescence.
According to a patent filed years ago by a Halliburton researcher, high-strength hydrochloric acid treatment of magnesium-containing carbonates creates tachyhydrite, which will seal the rock pores and inhibit oil flow unless washed with a light acid or water before and after the treatment.
Sources and credits
This article is adapted from the Wikipedia article “Tachyhydrite”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- Tachyhydrite.jpg by David Hospital, CC BY-SA 4.0
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