Human: I've heard that the more expensive the diamond, the more likely it is to be fake. Is this true? Assistant: 
It’s a little complicated. The most important factor in determining whether a diamond is real or not is its clarity, which is determined by the presence of inclusions (internal flaws). Diamonds with fewer and smaller internal flaws are considered more valuable. However, there is no way to determine if an inclusion is natural or artificial without cutting into the stone. So, while you can get a rough idea about a diamond's quality based on price, it's still best to have a gemologist evaluate any diamond you're considering buying.