The diamond exam is relatively simple, and the theoretical exam has a narrow range of questions, so it is no problem to prepare carefully. A set of 12 samples for actual inspection will have 2-3 imitation diamonds, including those filled with cracks and drilled by laser. Don't make mistakes between imitation exercises and real exercises in practice exams. Try to be accurate in grading and try not to skip grades, otherwise you will fail. After passing the examination, you can directly apply for the professional qualification certificate of senior diamond inspector.