Mixture of natural green earth, iron oxides and chromoxide green. In Italy, many mineral deposits of green and greenish minerals were available in Tuscany during the Middle-Ages. The medieval mineralogist could easily distinguish between green earths and green copper compounds. However, the green earths were named after the place of their origin. The individual deposits of some green minerals were sometimes scarce but on a regional scale they were plentiful. Epidote, for example, can be found as veins and thin layers up to 1 cm thick, in the area around Livorno, in Italy.
Kremer, pigments, Color Lab, Visual + Material Resource Center