Adventure in Diamonds was part of an attempt to position Miranda as a European star in the style of Dietrich and Greta Garbo.

[3] Captain Stephen Dennett of the Royal Air Force is aboard a passenger airliner flying to South Africa, when he meets the beautiful and glamorous Felice Falcon.

Felice schemes to use Stephen for the plot, using her charm to persuade him to permit her entry to the forbidden area because of his status as a military officer.

She is sentenced to prison but is offered a parole by Lansfield if she agrees to help catch a new ring of jewel thieves operating in the area.

[4] In a contemporary review for The New York Times, critic B. R. Crisler called the film "a crackling good second-rate melodrama" and wrote: "The world may never see a gem-lifter who is as glamorous as Isa Miranda and still has to go to the South African mines for diamonds, or a hero who is completely honest and yet as fascinatingly urbane as George Brent ...