[3] It has also been reported from the Zeilberg quarry, Maroldsweisach, Bavaria; at Boisséjour, near Clermont-Ferrand, Puy-de-Dôme, Auvergne, France; the N’Chwaning mine, Kuruman district, Cape Province, South Africa; in the US, occurrences were found in spurrite-merwinite-gehlenite skarn at the 910 level of the Commercial quarry, Crestmore, Riverside County, California[7] and in the Lucky Cuss mine, Tombstone, Arizona.

[8] In concrete chemistry, ettringite is a hexacalcium aluminate trisulfate hydrate, of general formula when noted as oxides: or Ettringite is formed in the hydrated Portland cement system as a result of the reaction of tricalcium aluminate (C3A) with calcium sulfate, both present in Portland cement.

[9] The addition of gypsum (CaSO4·2H2O) to clinker during the grinding operation to obtain the crushed powder of Portland cement is essential to avoid the flash setting of concrete during its early hydration.

From observations on dehydration and chemical formulas there were suggestions of the structure being composed of Ca2+ and Al(OH)3−6, were between them lie SO2−4 ions and H2O molecules.

[13] Further studies conducted on synthetic ettringite by use of X-ray and powder diffraction confirmed earlier assumptions and analyses.

[15] Ongoing research on ettringite and cement phase minerals is performed to find new ways to immobilize toxic anions (e.g., borate, selenate and arsenate) and heavy metals to avoid their dispersion in soils and the environment; this can be achieved by using the proper cement phases whose crystal lattice can accommodate these elements.