When I become lucky to propose to someone, I am not going to go down the route of a diamond that everyone else has. Something more precious like Morganite or Alexandrite (unless they can be lab grown too?)
When I proposed to my wife I went with a Sapphire as the main stone, mostly because I personally find clear rocks boring to look at (and my wife generally agrees).
Sapphire is beautiful, and available in a wide variety of colors.
The cool thing about Alexandrite is that it changes color depending on the type of light falling on it. It looks different indoors versus outdoors, for example.
And Alexandrite is considerably more rare than most diamonds, at least so-called "white" diamonds.
Now, red diamonds, those are exceptionally rare -- I think a sum total of ten are known to exist in the world, at least when it comes to natural red diamonds. And there was a really big deal made in the last few years when someone discovered what might have been the eleventh known red diamond, but I don't recall if it got officially ruled as "red", or if they decided it was some variant of "pink" instead.
