I am reading Skellig by David Almond. On page 41 it says "The house was blackened stone". I don't really understand what "blackened stone" means. If someone can help, I'd really appreciate it.
I suggest you go to Cologne, and look at the Cathedral. It is in fact made of white marble, but the people of Cologne prefer it in its current smoke-blackened state, and will not wash it.
