I'm really picky about my Amethysts--generally, dark, but not TOO dark a purple (you just have to have light be able to get into the stone and bounce back out!) and often with red or blue highlights, depending on the stone and the direction of the light.

This pair of nice deep purple stones are 8mm rounds and set into a traditional basket setting hanging from a leverback earring. Notice the thickness of the gold in the mounting. These are substantial, without being weighty. I like my stones well protected, and i assume you do too!