Copley Medal and Nobel Peace Prize (medal).

Refer to web site: http://nobelprize.org/nobel_prizes/physics/laureates/1915/wh-bragg-bio.html.

The use of X-rays as an instrument for the systematic revelation of the way in which crystals are built was entirely due to the Braggs. This was recognized by the award of the Nobel Prize jointly to father (William Henry Bragg) and son (William Lawrence Bragg) in 1915.

Nobel Prize medal is 6.3 cm in diam, and the Copley medal is 4.1 cm in diam.