About nephrite, like jadeite, it has other stones that are sold as 'nephrite', like serpentine. This is the stone that is found both around nephrite and jadeite dikes. In the zones where jadeite and nephrite is formed, in the areas where the temperature and pressure change, the minerals and fluids don't crystalize the same way and serpentine is formed. There is a lot of serpentine, much more so than jadeite and nephrite. It has somewhat of a similar look to nephrite and is sold as jade. It is not jade and is much weaker. It can easily be dyed and carved. Many of the carved pieces being sold as high quality nephrite are actually serpentine. Prospectors use serpentine as a sign that jade maybe near by.
The geologic conditions needed to form both jades is extreme, although more so with jadeite. With jadeite, it is found in areas where the subduction of one tectonic plate goes under another. Here fluids, temperature and pressure form jadeite over millions of years. Then, that the jadeite must go through a second journey by being pushed up through the layers in mountains. This is where people find the jadeite. With nephrite, subduction is not required, but it requires intense pressure and temperature and hence is found in fault zones, like along the coast of north, west and south America and north into Alaska.
The geologic conditions needed to form both jades is extreme, although more so with jadeite. With jadeite, it is found in areas where the subduction of one tectonic plate goes under another. Here fluids, temperature and pressure form jadeite over millions of years. Then, that the jadeite must go through a second journey by being pushed up through the layers in mountains. This is where people find the jadeite. With nephrite, subduction is not required, but it requires intense pressure and temperature and hence is found in fault zones, like along the coast of north, west and south America and north into Alaska.
