I just dislike them, since everyone looks up to them.. due to De beers and others iron grip on the market even overpriced. Way overpriced.
The availability is way greater then the demand.
But much is just locked in, in vaults as to keep the looks up that it would be rare.
Just go to most jewellery stores; almost every store carries diamond rings.
Now take a rare gem; say benitoite, how many jewellery stores carry them? Just about none.
If so many have them, can they be rare? I doubt it.
Benitoite is the state gem of California, gem quality material is found only in two mines I think.
Both mines are located in California. More detailed reading below:
You do realise your next to asking for a whole list here, right? lol
Diamond is so far the only one I really dislike. So far.
Some of my favourites are:
Garnet - it's really a group with several species.
But most of them are easy to cut and polish into gems, even for a beginner.
Corundum - Ruby and sapphire.
Very hard, but a pleasure to work with. Sadly, the rough is getting quite expensive.
Precious Opal - Very variable and good looking rock. A (fun) challenge to orient the rough correctly.
Aussie opal still tops it, IMO, although I know many like the Ethiopian stuff.
O My Goodness! I love asking questions. I ask google all the time. Here is a great site that might answer some of your questions, & you might possible want to take a class. Rock Identification Tables do some digging around on this site. It's full of info. & never stop learning