It can be confused with cobalt-rich adamite when its color is purple. It lacks adamite's luster, though, and adamite's dome termination is not slanted, as creedite's is. Creedite's purple color is attractive and its crystal form is unique, making creedite a nice mineral collection addition.
Color is white, colorless and purple.
Luster is vitreous. Transparency crystals are transparent to translucent. Also acicular crystals in radiating groups. Cleavage is perfect in one direction. Fracture is uneven.