<human>: Is there a way to determine if a diamond is fake?
<bot>: Yes, there are ways to determine if a diamond is fake. One of the most common methods involves using a gemological instrument called a refractometer. This instrument measures the refractive index of a stone and compares it to known standards for diamonds. If the results don't match up with what's expected for a diamond, then it can be determined that the stone is likely not genuine.