When a penis becomes abnormally hard. This only occurs when a man is so turned on that he cannot think straight and becomes light headed. It is usually at the climax of an orgasm. It begins with light grunting but eventually leads to loud and sharp screams. An Idaho Diamond also has the potential to rip the skin of an anus when inserted beforehand. It is called an Idaho Diamond because the erection is as hard as a diamond.
by That's So Hard Like a Diamond January 10, 2011