CZ vs. Diamond: Is Your Ring Real?

Question
I have ring marked 925 dqcz.I took the stone out and put it in water and it sank to the bottom immed.

Answer
Hi Jo
Generally rings marked as CZ have cubic zirconia & not a diamond. However, if the stone if of a decent size such as 0.50 cts. Or more, I would recommend that you get it tested by a Gemological laboratory.
Best regards
Sambhav Karnawat
http://www.jewelove.in