There is no difference between water foam and water foam jade. Water foam jade and hornblende black jade, hornblende flower pieces, and calcium aluminous garnet are called the four major killers of jadeite. They are often used to make imitations and substitutes of jadeite. The semi-transparent water foam jade looks very similar to ice jadeite, and observation of luster can distinguish jadeite from water foam jade.
Shui Mozi was also called Shui Mo Jade, which referred to the same type of jade. Shui Mo Jade was called one of the "Four Killers" of jade, and was often used to make imitations and substitutes for jade. The other three types were hornblende black jade, hornblende flower pieces, and calcium aluminite garnet.
Water foam jade is composed of albite aggregates. Most of them are pure white or pink white, and some of them contain dark green color spots, which are quite similar to mossy agates. The semi-transparent water foam jade looks like ice jadeite, and it is most likely to be confused with ice jadeite.
Jade can be distinguished from water foam jade from its luster observation. Jade belongs to jadeite, with a higher refractive index and generally strong reflectivity. Although water foam jade has fine grains and good transparency, its grease-glass luster is not as strong as that of jadeite.