Nephrite as a surface treatment. A lot of nephrite tools and amulets are known since the Early Neolithic (VII mill. BC) to the Late Chalcolithic (V mill. BC) on the Balkans (mainly Bulgaria; also in Greece, Serbia, Croatia) from two or more unknown sources - Balkan "nephrite culture". Such tools are found in the Later Neolithic of Poland (from the most probable local source Jordanów), Sardinia (Italy) (unknown source) and Switzerland (Kostov, 2005; 2013). Single or just a few finds of nephrite artifacts are reported also from some other European countries. During Neolithic times, the key known sources of nephrite jade
Theory of forms Theory of forms The theory of Forms or theory of Ideas is a philosophical theory, concept, or world-view, attributed to Plato, that the physical world is not as real or true as eternal, absolute, unchangeable ideas. According to this theory, ideas in this sense, often capitalized and translated as "Ideas" or "Forms", are the non-physical essences of all things, of which objects and matter in the physical world are merely imitations. Plato speaks of these entities only through the characters (primarily Socrates) of his dialogues who sometimes suggest that these Forms are the only objects of study that can provide