Iolite definitely kicks ass!
That's my latest loose gemstone I'm on the look out for.
A good color changing alexandrite can amuse me for hours.
Garnet in its rainbow colors knocks my socks off (standard deep red, mandarin orange-yellow, tsavorite green, spessartite deep orange). And it's 8.5 on the hardness scale, so it's durable.
But Aye! Corundum! 9.5 on the hardness scale, good sparkle. I am currently mesmerized with my latest pendant/ring made up of red (ruby), cobalt blue and yellow sapphires. Yikes!
Still... diamonds (check out the colored ones, too) are king. Maybe because it's carbon based like all life here on earth; it's a thing of raw natural beauty regardless of social hype. I agree about the shady business and blood. The gemstone business is tough all around.
WinAce, try getting a high quality ruby or alexandrite compared to a diamond. Diamonds are much less rare, and relative prices reflects this (i.e., diamonds are cheaper).