The 1924 Nobel Prize in Physics awarded to Swedish physicist Karl Manne Georg Siegbahn, ‘for his discoveries and research in the field of X-ray spectroscopy.’ Includes the iconic Nobel Prize medal housed in its red leather case, and beautiful hand-illuminated diploma in its ornate blue morocco leather folder. This was an uncommon ‘reserved’ prize from 1924, presented to Siegbahn by the Nobel Foundation in 1925. In 1924, the Nobel Committee for Physics had decided that none of the nominees for the award met the criteria outlined in the will of Alfred Nobel, and subsequently granted the open prize to Siegbahn in the following year.