The famous "black prince ruby" named after the son of UK King Edward III,for the black prince get the ruby and named it.It weight 170 ct or so,
it is collected by the UK royalty for several centuries,and set right on the center of the UK crown .
At a battle fight against French,King Henry V's head was hit hard,but he was protected by the helmets , and the "Black Prince Ruby" set up in the helmet was not broken,either, so it was treasured and collected for memory.
