His involvement as a principal investigator in the analysis of Moon rocks collected in the Apollo program brought him to the attention of the British media and public.
[2] He went to join the staff at Manchester University in 1938, and in 1939 on the outbreak of World War II was put to work studying industrial slag mineralogy in order to improve the efficiency of the furnace process.
He took in hand an extensive but ill-organised collection of meteorites in the museum and from his study with the electron probe discovered the "Agrell effect", the decrease in the nickel content of kamacite as a boundary with taenite is approached.
As he came to the end of his career during the 1970s, he passionately wanted Cambridge to remain a centre of extraterrestrial sample research and attracted talented workers to form a flourishing planetary sciences group there.
Retirement made little difference to his level of activity and the award of a Leverhulme Emeritus Fellowship allowed him to return to the Marysvale district of Utah to continue work he had started in the 60s.
Agrell was an outstanding optical mineralogist and pioneer of precise chemical analysis for petrographic studies, Although he was an excellent communicator, he was a poor formal lecturer partly because of a slight stammer and he disliked writing because of a mild dyslexia.
[7] Agrell married Jean Elspeth Imlay, a former fellow graduate student at Cambridge whose skills included fluency in Russian and computing.