Question: When did the former wife of Graf von Bismarck-Schönhausen donate a piece to the Smithsonian she purchased on her honeymoon with a different man?
Sentence (from "Bismarck Sapphire Necklace"): The sapphire itself was mined in Burma (now Myanmar, and was purchased by the Countess in Sri Lanka in 1926 during her honeymoon with Harrison Williams.
Relevant evidence: Yes