Valpolicella Ripasso is a form of Valpolicella Superiore made with partially dried grape skins that have been left over from fermentation of Amarone or recioto. Winemaking in the region has existed since at least the time of the ancient Greeks.
Barium chloride, or any other barium salt, should burn with a green flame. When a barium salt is burned, the thermal energy is transferred to the outer electrons of the barium ions. They gain enough energy to excite them to a higher energy level. They then drop back to their ground state, releasing energy.
Fire Scale or Fire Stain is also oxidation but, it is below the surface of the metal. Sterling silver is very prone to firescale. Firescale/stain is a gray/blue/purple coloration that forms in the top layers of the metal. See the beginning of this article (updated 1/16/17) for the reasons that this happens.