How is greenstone made?
Greenstone, also known as greenschist, is a non layered
metamorphic rock derived from basalt, gabbro or similar rocks
containing sodium-rich plagioclase feldspar, chlorite, epidote and
quartz. Chlorite and epidote give the green color. New Zealand Jade
or Greenstone ( Pounamu in Maori ) comes in four main types:
Kawakawa, Kahurangi and Inanga are Nephrite or Calcium Magnesium
Tangiwai is Bowenite or Iron Magnesium Silicate.