There are a couple of other arsenate minerals that have similar names to pharmacolite, namely pharmacosiderite and picropharmacolite . Despite having similar names and being arsenic mineral they are otherwise unrelated. Pharmacolite is related to a few minerals that have a similar formula and structure. Of these only gypsum is common. O Brushite .
Color is white, colorless or gray.
Luster is vitreous to pearly. Specimens are translucent to transparent. Crystal System is monoclinic. Crystal Habits include acicular crystals and botryoidal crusts and masses. Cleavage is perfect.