“This type of loss is called a “mysterious disappearance.”” Some insurance companies cover mysterious disappearance, others don’t, so you will want to confirm whether it is included in your renters policy.
Furthermore, most renters insurance policies have a limit on the amount they will pay out if jewelry is stolen or lost. In order to make sure that your jewelry is fully covered, you would need a separate policy designed for valuable items called a “personal article floater.” This would provide added coverage on top of what is already provided by your insurance plan.
If the ring has a high value, the insurance company may require an appraisal to be on file or proof at the time of loss before extending coverage.”