Jade is actually the gemstone name for two different mineral forms, Jadeite and Nephrite. Nephrite jade is the most commonly used variety of Jade.
Mineral Species: Jadeite or Nephrite
Chemical Formula: Jadeite NaAlSi2O6 or Nephrite Ca2(Mg,Fe)5Si8O22(OH)2
Mohs Scale Hardness: 6 - 7
Location: China, Africa, Burma, Russia, USA.
Typical Appearance: Can be yellow, red, black, green, white, or purple.