High Quality Content by WIKIPEDIA articles! Ye'elimite is the mineralogical name of calcium sulfoaluminate, Ca4(AlO2)6SO4. It gets its name from Har Ye'elim in Israel where it was first found in nature. It is alternatively called "Klein's Compound", after Alexander Klein of the University of California, Berkeley, who experimented with sulphoaluminate cements around 1960, although it was first described in 1957 by Ragozina. Ye'elimite is most commonly encountered as a constituent of sulfoaluminate cements, in which it is manufactured on the million-tonne-per-annum scale. It also occasionally occurs adventitiously in Portland-type cements. On hydration in the presence of calcium and sulfate ions, it forms the insoluble, fibrous mineral ettringite, which provides the strength in sulfoaluminate concretes.