Surprisingly, though a form of Jade, Nephrite is not a mineral of its own but instead a form of Actinolite (the other varieties of actinolite are not similar to Nephrite or Jade). The other form of Jade is Jadeite, but the two are distinct from each other despite similar appearances. Nephrite, for instance, is typically only green or white but Jadeite has a plethora of colors.
Nephrite's name is actually related to its early uses and it is derived from the Latin "Lapis Nephriticus" which means 'Kidney Stone'. It is used to cure Kidney illnesses, and is supposedly good for emotional balance. It helps to keep the heart and kidneys functioning at peak health. It also helps to clear out negative energy.
Notations on Wearing Nephrite:
It is associated with the sign Pisces.