Formula: Ca₂Co(AsO₄)₂ · 2H₂O Co may be replaced by minor Mg.

Species:

Colour: Rose-red, pink; rose coloured in transmitted light

Lustre: Vitreous, Sub-Vitreous, Resinous

Hardness: 3½

Specific Gravity: 3.46 – 3.74

Crystal System: Monoclinic

Member of: Roselite Group

Name: Named in 1824 by Armand Levy in honor of German mineralogist Gustav Rose (1798–1873), Professor of Mineralogy, University of Berlin.

Type Locality: Rappold Mine, Neustädtel, Schneeberg, Erzgebirgskreis, Saxony – Germany

Dimorph of: Anorthoroselite

Isostructural with: Brandtite, Wendwilsonite