It would be similar to evaluating a cut gem only you will have to get a cutter to roughly determine the estimated yield per the size, weight, clarity, shape, etc...
Also if it were mine and they were in the 5+ carat range of rough I would send the best one or two to AGL or GIA or a accredited lab near you to determine if the gems are natural, and if there is any treatment to the gems. If everything came out good I would have those two cut; then proceed to the next ones and get a paper on each one if it yields over a 1 carat well cut clean gem... It assures you they are what you thought they were and the buyer of your stones will also know. But I would only send one or two of the rough gems to be tested in their rough state; and the others after they were cut.
A gemologist will help but not like the lab as they can issue a report on rough as I have had GIA examine rough before I spent the labor and time to cut it to make sure it was what I thought it was.
That is just my humble opinion though.
Good Luck as the shapes and colors look rather nice.
Jake, the piece you are holding in your hand looks very suspect to me. There is A LOT of lab created ruby being sold as natural ruby rough. Dana has a very good plan laid out for you before you go too far with these.