Sorry not to answer you sooner. My computer only works when it wants to. to the best of my knowledge, the stones are only glass. I have lost my jewelers loupe and even with a magnifying glass I cannot see well enough to see if the stones are prong set. They appear to be but I honestly can't tell. The ring is not an expensive one but it is gold filled which will last a lot longer than plated and it is very pretty. bright and shiny. I will guarantee anything I sell for a reasonable period of time. The stones should not fall 0ut unless you hit it hard against something. By the way for future reference, even prong set stones can fall out. I lost my engagement ring that way. The prongs catch on something and pull out, loosening the stone. You should always check them periodically. A friendly jeweler will do it for you.