"Look at it this way, the kind of person that places a high emotional value on a diamond is not going to feel the same way about a $50 diamond as they would a $3000 diamond."

However, the kind of person who places a high emotional value on showing off the diamond to other people may. "Reliably discernable" by a lab is one thing. "Reliably discernable" by friends, family, and random people on the street is quite another.