An organic chloride salt that is the monochloride salt of crystal violet cation. It has been used in creams for the topical treatment of bacterial and fungal infections, being effective against some Gram-positive bacteria (notably Staphylococcus species) and some pathogenic fungi (including Candida species) but use declined following reports of animal carcinogenicity. It has also been used for dying wood, silk, and paper, as well as a histological stain.