Interestingly it's been possible to make rubies for years, 150 years ago rubies were far more prized than diamonds, but then fell out of fashion, mostly because diamonds were in good supply and there was a big marketing campaign for them. Consequently lab grown rubies are pretty cheap - maybe $50 carat, but here's the thing.. natural rubies are still expensive because they are rare and contain impurities that give them a glow/fire that is prized.

But here's the fun thing. You can destroy the value of a natural ruby by cooking it. If you heat it in the right way the impurities will anneal out and you will be left with a near flawless stone that appears to be artificial! Bye bye value :)