Nephrite Greek "λίθος νεφριτικός"; "νεφρός λίθος", which means 'kidney stone' and is the Latin and Greek version of the Spanish "piedra de ijada" (the origin of "jade" and "jadeite"). Accordingly, nephrite jade was once believed to be a cure for kidney stones. Besides the terms already mentioned, nephrite has the following synonyms and varieties: "aotea", "axe-stone", "B.C. jade", "beilstein", "kidney stone", "lapis nephriticus", "nephrit", "nephrita", pounamu, "New Zealand greenstone", "New Zealand jade", "spinach jade" (dark grayish green), and "talcum nephriticus". "Tomb jade" or "grave jade" are names given to ancient burial nephrite pieces that have a brown or chalky white texture
Theory of forms admitted were impossible to know. Nevertheless, he formulated a very specific description of that world, which did not match his metaphysical principles. Corresponding to the world of Forms is our world, that of the shadows, an imitation of the real one. Just as shadows exist only because of the light of a fire, our world exists as, "the offspring of the good". Our world is modeled after the patterns of the Forms. The function of humans in our world is therefore to imitate the ideal world as much as possible which, importantly, includes imitating the good, i.e. acting morally. Plato