Matthew Wilson remembers the day a newly engaged customer came to get her two-carat ring appraised.

"She was beaming," says Wilson, an owner of the Scarsdale jeweler Wilson & Son.

Wilson's brother took out the microscope to examine it and knew immediately that it wasn't a diamond.

"You have to find a tactful way to ask instead of saying, 'Your stuff is junk,' " Wilson says.

When he told her the stone was cubic zirconia and not a diamond the woman ran out of the store crying.

"To this day, we don't know if her fiance' knowingly purchased cubic zirconia because he couldn't afford a diamond or if he went to buy a diamond and was sold cubic zirconia," Wilson says.

Proposing marriage might not be the appropriate time to present your significant other with a faux diamond, but Valentine's Day just might be.

Read more about the trends in faux diamonds at http://www.thejournalnews.com.