Tried to get a good photo of these to see if they help a bit. But this is probably why we're having some much trouble.
Technically - there are 4 amethyst in this photo.
On the other hand, there are 4 citrines in this photo.
There are probably 5 imposters in this photo.
Starting at the very top is an over-irradiated smoky quartz which I bought just because it was so overly black. Quartz is fairly common but true smoky quartz is hard to find so these days a lot of the smoky quartz on the market is just regular quartz that's been irradiated to create the effect that takes nature eons to create. And sometimes that quartz gets a bit too much of a good thing and creates a weird shiny black quartz. So, an imposter.
Below it is one I can't identify beyond - well, it's probably a quartz. It's either a very murky amethyst or a weird smoky quartz verging on purple. Or someone started with amethyst and ended up with whatever that is, possibly aiming for citrine.
The three yellow tumbles below it are - heat-treated amethyst sold as citrine. A lot of citrine on the market is heat-treated amethyst just because amethyst is more common. And there are times when I prefer working with it over true citrine because for me, the energy feels smoother.
The point below those is a true citrine in a nice yellow color. True citrine can be expensive (compared to the heat-treated stuff) and these days, dealers will often identify where the mine was to help reassure it's authenticity.
Now generally no one "fakes' amethyst or rose quartz because those are common enough. But cherry quartz and strawberry quartz are usually an "enhanced" stone rather than a natural stone.