This happens because of a displacement reaction. You have a solution supersaturated with a copper
salt, and you add a metal ion that is more reactive than the copper,
which steals the cation from the copper salt, leaving a bunch of
disassociated copper ions in solution. If you drop the copper penny into
it, it provides a nucleation site for the copper ions to deposit
themselves, producing what you see in the image. (Source)
Simon:listen…my dream boy is tall with long dark hair. multi-talented. i’m talking violinist, intelligent, excellent athlete. loves cars and dresses sharp. powerful magician. a bit brooding but a romantic at heart. Grey eyes and witty humor. rocks a nice pair of jeans. maybe his name rhymes with chaz switch, i don’t know, just dreaming here.