Here is the information for the film you requested, (The Diamond Polisher).
Since "Slefuitorul de Diamante" is not a mainstream Hollywood title, it is most likely the Romanian-dubbed title for one of two specific films. Based on the direct translation and common Romanian dubbing history, here are the two possibilities: The film is likely The Diamond Polisher (a Romanian documentary or short) OR a direct-to-video action film. slefuitorul de diamante film
Are you looking for the Leonardo DiCaprio film ( Blood Diamond ) or a specific Romanian documentary/short film about actual diamond polishing? Here is the information for the film you