My wife wanted a sapphire and we met during Ph D research. It's straight up not possible to pay more then like, a dollar for a synthetic sapphire so that's what's in her ring.
I like my scintillator crystals.. they're purpose built to be very fluorescent
If you wanted you could even diy your own sapphires and rubies. It isn't a complicated process, but im sure its finicky to get everything perfect.