Formula: Zn₂(AsO₄)(OH) · H₂O

Species:

Colour: Yellow to colourless; pale yellow to colourless in transmitted light.

Lustre: Vitreous, Sub-Vitreous, Resinous, Waxy

Hardness: 4½

Specific Gravity: 3.98 – 4.01

Crystal System: Monoclinic

Name: Named in 1932 by Julien Drugman and Max H. Hey in honor of Mr. Louis C.A. Legrand (1861-1920), a Belgian mining engineer and mineral collector who collected the first specimen.

Type Locality: Flor de Peña Mine, Lampazos de Naranjo (Lampazos), Lampazos de Naranjo Municipality, Nuevo León – Mexico

A secondary mineral occurring in the oxidized zones of arsenic- and zinc-bearing deposits.