Gem Minerals
Jadeite/Nephrite
What it is
Two different minerals both called jade. Jadeite is a pyroxene (sodium aluminum silicate), rarer and more valuable. Nephrite is an amphibole (calcium magnesium silicate), tougher and more common. Both are extremely tough due to their interlocking fibrous crystal structure.
How it forms
Jadeite forms under very high pressure and relatively low temperature in subduction zones where oceanic crust dives under continental crust. Nephrite forms in metamorphic rocks where serpentinite contacts other rock types.
NaAlSi₂O₆ (jadeite) / Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂ (nephrite)
