To get an idea of what diamonds are really worth, investigate what you can get for them when you pull them from a find. The answer seems to be that unless it is at least a third of a karat, no one will pay you anything for them. Rubies are almost a career in themselves. Even unaltered, there is an amazing variety of types.
My local coin guy who scraps gold has a small vial of a few dozen assorted stones from rings and earrings that I keep trying to trade him out of. Theres a few nice red stones in there but I haven't pushed it so far as to look at them under a handlens. He knows I may be able to tell what they are and it would drive the price up, so I am taking a shot in the dark.
To answer the OP, probably the easiest (and maybe most lucrative) thing you can do is sell them on something like the e auction site whose name will not be named here or craigslist. People overpay all the time there. If you need to know what you really have, getting appraisals is the best way. For the least best way, post pics here and see what the hive mind has to say. Be sure to include something so we can judge scale on your pics.