Nephrite Jade
Nephrite jade is a variety of calcium, magnesium and iron rich amphibole minerals tremolite or actinolite. These minerals get twisted and pulled like taffy under the surface of the earth until the fibers are intertwined.
Nephrite Jade is the true jade of ancient China and was first used and imported into China, 3000 years ago and was a most prized possession. it wad used for utensils, tools, jewelry and weapons.
Nephrite Jade has a very fibrous and strong structure. It has a lower hardness making it great to carve and was affectionately nicknamed the "super skull crusher" due to its durability.
Most nephrite jade is a spinach green, often with black or dark green flecks in it. Brightness, translucency and color are what determines the price of a piece of jade.