Seems like there are a lot of posts asking about this, so I thought I'd start a specific thread on it. Below is a verbatim copy of the warranty. This warranty has been in the package of every piece of Dmq jewelry I've ever gotten from QVC, so I'm kinda surprised that people who have bought from QVC don't know about it. QVC really ought to post the warranty on QVC.com.
"LIFETIME LIMITED WARRANTY
Your Diamonique simulated gemstone jewelry has been crafted to the highest standards. The quality of the Diamonique simulated gemstone is guaranteed for as long as you own it. We will replace the simulated gemstone in its original setting should it become damaged (chipped, cracked, scratched) or lose its brilliance. It will also be replaced in its original setting if it is lost due to a defect in the manufacture or workmanship of the setting."