Some of you are undoubtedly considering a sexy, lucrative career in the rarified world of cat burglary. For all you would-be dapper scoundrels, here's a recent medical paper that'll be of interest. It's about the dangers of swallowing your prizes.
In "An Unusual Digestive Foreign Body" (which deserves some sort of academic prize for pithy understatement), Jean Louis Frossard and Raymond de Peyer of the University of Geneva bring us a case study about a diamond theft gone (literally) south:
A 36-year-old man involved in the burglary of a precious diamond was surprisingly found at the crime scene by a security agent while he was just holding in his hand the precious stone. To keep the stone in a safe place during the battle with the security agent, the thief put the stone in his mouth and swallowed it. Once the thief was arrested by the police, he was kept under surveillance and the stools were screened to retrieve the stone. Unfortunately, the bowel movements of the suspect were rare and the stone was not evacuated in a timely fashion. The patient was then referred to our hospital for an abdominal X-ray [...] as recommended by current medical and forensic guidelines [...]
The abdominal X-ray showed the stone in the cecal area. Because of court order, we shortened the waiting time until natural expulsion. Therefore, the patient underwent a total colonoscopy in the presence of police officers that easily allowed uncommon stone retrieval using a basket catheter [...] This case illustrates the feasibility of unusual colonic foreign body retrieval even in the proximal segment of the colon [...]
And here's a view of the diamond via an endoscope from the bottom up. To all you novice A.J. Raffles and Lupin the Thirds out there, please remember that the world is not a Looney Tunes cartoon. That which goes in must come out, and INTERPOL's jurisdiction does not stop at your U-Trau. You can read the full paper at Case Reports in Gastroenterology.