Crystal system: Monoclinic.
Cell salt: Hydrous phosphate of iron.
Colour: Blue, green, or colourless when freshly excavated, but darkens when exposed to light.
Planet/sign: Venus-Neptune/Pisces (exact cell salt equivalent).
Uses: Vivianite regulates the delicate endocrine system. It aids us in defending the body-earth against disease by instilling in us a positive mental outlook on life. This stone may be useful for treating severe depression and as a preventative medicine when the body is threatened by illness as a result of long-term, negative mental and emotional state of consciousness.