To avoid excessive seriality, stones with various hues were exploited to reproduce apparently very similar artworks, actually very different in the pictorial rendering. A skillful example of the representation of the same model with different stones are the two panels with a sunflower, made in 1664 following the prototype by Girolamo della Valle. They were created using two different classes of stones, hard stones and calcareous, also named “soft stones”. The panel made with soft stones seems to be more successful, due to the shades of the Arno jaspers, that enlight the corolla of the flower, in strong contrast to the green leaves.
