Adding Dead Coral and Cowrey Shells to New Tank

Hi guys!

Just one more quick question: we're cycling our 60 gallon tank (currently in week one).

My husband and I wanted to add a bunch of beautiful dead coral and cowrey shells that we have collected from Hawaii over the past few years. Is it safe to add these to our tank? We've had them for a few years now and they're absolutely stunning.

I thoroughly rinsed them and thought now would be a good time to add them since we don't have any fish in the tank yet.

Thanks so much! Happy Saturday. :-)