standard for scrap to have refined but all gold will be melted by the refiner and the seller will be paid for the pure recovered less fees. The price paid will usually be based on the daily London fix. The person to whom you sell your scrap to will offer you a price per pennyweight based on the karat weight of the gold you give him. You should be aware of what is 10K, 14K, 18K etc because the value of each karat weight is different. Unless you can sell directly to a refiner(unlikely) you will have to have an idea of what you have so you know the middleman is paying you a fair price. Check the daily price in the paper (Precious Metals) and do some quick math.
The problem with selling scrap as an individual is finding someone who will pay you fairly, allowing himself a profit margin too. He has to take a chance that the assay of his scrap will come out in his favor and that the price of pure has not dropped between the time he bought your junk scrap until the day he is paid.(usually after it is refined)
It is not an easy business to get rid of junk stuff but now that gold is so high, it is worth the trouble.
http://www.democraticunderground.com/discuss/duboard.php?az=show_topic&forum=403&topic_id=175