Hamilton says, “I’m a diamond in the rough, a shiny piece of coal.” What does he mean by this? What does this line show about his character?

I think Hamilton was unlike any other politician. He was a Founding Father who was never elected President. Hamilton was aide-de-camp to George Washington during the Revolutionary War and devised the successful plan for ridding the new country of its potentially devastating war debt. Alexander Hamilton observed slavery in that time and the gruesome and horrific way that slaves were treated might have shaped his view on the liberation and equality of all people in America. This was certainly special for a politician at the time.