I knew a
Crystal back in middle school, not sure what her MN was. And I know a
Krystal now, her MN is
Marie. I never heard either one complain about their name,
Krystal has a bit of trouble with the spelling but people get it after she explains it once. Personally I think it is a very dated and tacky name that should remain in the 80s. Some words work as names, and some don't.
Crystal, no matter the spelling, is on the don't list.