There is no magic link or book to identify marbles. There were and still are many millions being produced weekly and monthly. I know of no one who knows how many different varieties, sizes, color combinations, etc. that have been made since Roman times or before. The two major groups are handmade and machine made. Both of these groups can be old or newer. It take years of effort time and work to identify 25-50% of the marbles you will see. All the marble questions have never been answered yet. Marbles can be a lifelong learning process. Learn what a old handmade marble is, a machine made, a corkscrew, different types or styles, on and on. Learn before buying. Buy what you know. Buying blind can with time get expensive and then end up with nothing much for the money and time. There are hundreds of fake marble bags and packages out there. There are fake marbles out there, beware. Any marble collector that has collected for a few years, has purchased a fake. Marble collecting has many life time rewards of many types. One of the best is the close friends made over years. Some marble shows are like a family reunion.