Chalcosiderite is in a solid solution series with the mineral turquoise . A solid solution series occurs when more than one element can occupy the same space in a mineral's structure and freely substitute for each other. Chalcosiderite and turquoise have the same structure, just slightly different chemistries. O and is the aluminum rich end member of the series. Chalcosiderite is the iron rich end member and it is the coloring effects of the iron that produces the darker color for chalcosiderite as opposed to turquoise's lighter blue-green.
Color is green.
Luster is vitreous. Specimens are translucent to less often transparent. Crystal System is triclinic. Crystal Habits include tiny prismatic to tabular crystals and crusts. Cleavage is perfect.