I now have three pairs of these, with different colored gemstones.  They are quite attractive and seem to be a decent quality....especially for the price.  None of the stones seem to be at all loose, like one of the reviewers experienced.
They are a great size for me, as I don't like huge earrings.  These just flow around the ear very nicely and add a bit of color to enhance what you may be wearing or your eyes.  I always get comments on my eyes, when I wear the blue ones!
I really love them and this is generally my earring of choice, whenever I am heading out and about.
The earrings fit nicely and backs stay on very well.  I love the way that they "shape" themselves around the ear lobe!