Sust. FEM. plur. of gehlenita: Ca2Al2SiO7, ore of the Group of the melilita of the sorosilicatos class. It is a phyllosilicate of calcium and aluminium, analogous to other calcium silicates of this group, containing other metals instead of aluminum. It is a series of solid solution with the oakermanita: Ca2MgSi2O7, in which gradually replaces aluminium magnesium and generates different minerals in the series. In addition to the elements of the formula, as impurities often contain iron, manganese, titanium, magnesium, potassium and sodium. The name is in honor of Adolf Ferdinand Gehlen, German chemist. Synonym: velardeñita, by Velardeña, name of a Mexican mine. (Source: 41 Wikipedia;