Jade JewelryWhere the name comes from: Spanish piedra de ijada - loin stone, from the reputed property of aiding disorders of the loins and kidneys. Also known as Greenstone.
Where the stones come from: China, New Zealand, Russia, Guatemala, Swiss Alps. Dark green "Canada jade" from Western Canada. The best stones come from Myanmar previously Burma
Chemistry: There are two distinct minerals that are known as jade. Nephrite Ca2(Mg,Fe)5Si8O22(OH)2 and Jadeite NaAlSi2O6
Colors: Nephrite is paler, pale green to white, jadeite is an intense green but can also be paler or with tones of pink, grey or violet.
...and another thing: The two forms of jade were not identified as being separate until 1863, nephrite was mostly used in China and New Zealand while jadeite, the rarer form was mostly used in Central America.