Ravens have a fascinating role in mythology, both the Greeks and the Native Americans seem to agree that they carry an uncanny potential, but could at times misuse their power, for which transgression, or sometimes dereliction of duty, they even change their color.
Based on the various raven myths from Greek, Norse or Celtic mythologies, ravens could be said to represent the ability to transform latent potential into actuality, for themselves and others.
A human who has a raven for his totem animal, might be very creative on the one hand, and yet be limited to some extent in their social circles.
A gemstone correlating to the raven energy could be tourmaline.
I could speak a lot about ravens, because they fascinate me, even their unique language, and they seem to return the favor. Whenever I leave the house, they follow me, and they even answer my imitation of their particular calls.
For others, presumably, because of their color, ravens could still be deemed the harbingers of evil, for me, it is pretty much like meeting a good old friend.