Nephrite and Jade
The material which thus came to be called jade was not the same as the mineral of like appearance that the Chinese had known for centuries. Chinese jade was what we now call nephrite, while the stone used by the ancient Americans has the modern name jadeite. Almost all of what is and was known as “true jade” is one of these two minerals. (Alas, the name of the Chinese species is not even of Chinese origin. When the Spanish for kidney stones was translated into Latin it became lapis nephriticus, which later became “nephrite.”) Jadeite and nephrite really have very little in common. At times they may look very much alike and both can be very tough, durable minerals.
Observed closely, the greens are not the same, even when both minerals are of good green color. The Spanish, for example, were able to generate some confusion between jadeite and emerald. This is possible because jadeite and emerald greens may sometimes approximate each other. Such confusion could not exist with the typical spinach green of nephrite. The differences in these hues are explainable because nephrite gets its green from the presence of iron in its composition, while jade-ite’s green—like that of emerald—arises from the presence of chromium. More diamond jewelry.