Human: How do I know if a diamond is real or fake? Assistant: 
You can check the 4Cs of diamonds to determine whether it’s real or not. The first step is to examine the cut and clarity, which will give you an indication of the quality of the diamond. Then look at its color, which should be consistent throughout the stone. Next, check for fluorescence, which indicates the presence of impurities in the diamond. Finally, use a diamond tester to test the diamond's hardness, as this is one of the most important characteristics of a diamond. If all four tests come back with positive results, then you have a genuine diamond.