Weilite is a rare arsenate mineral

Arsenate mineral

Arsenate minerals usually refer to the naturally occurring orthoarsenates, possessing the 3- anion group and, more rarely, other arsenates with anions like AsO32- or [AsO22]- . Arsenite minerals are much less common...

. It is a translucent white triclinic mineral with a waxy luster.

It was first described in 1963 for occurrences in Gabe Gottes Mine, Haut-Rhin, Alsace, France; Wittichen, Schenkenzell, Black Forest, Baden-Württemberg, Germany; and the Schneeberg District, Erzgebirge, Saxony, Germany. It is named after French mineralogist René Weil of the University of Strasbourg

University of Strasbourg

The University of Strasbourg in Strasbourg, Alsace, France, is the largest university in France, with about 43,000 students and over 4,000 researchers....

. It occurs in the oxidized zone of arsenic-bearing hydrothermal veins

Vein (geology)

In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation...

. It occurs as an alteration product of pharmacolite and haidingerite

Haidingerite

Haidingerite is a calcium arsenate mineral with formula Ca·H2O. It crystallizes in the orthorhombic crystal system as short prismatic to equant...

.