When it comes to marbles, there are no "simple" rules of thumb. Those pictured are modern Jabos. If you look at the construction, you can see that the majority are single fold types. Many will have what is referred to as the jabo "buttcrack", where the two sides fold together to form what sorta looks like a butt crack.
Chinese marbles are usually easily detected by the colors of glass and construction. They often have an orange peel type texture to the glass, as do many larger jabos. There are exceptions to every rule though... this is just a general observation, not applying to every case. Marble kings have their specific traits too. They have long seams on opposite poles that make the marble look as if it were made of 2 halves. There are so many things to look at in identifying marbles. The seams are usually the tell. When the seams don't tell, the glass does, or if it's a swirl with no seams, the glass and behavior of the ribbons in the swirl often tells. Some marbles are often difficult or even impossible to tell where they came from no matter how much of an expert you are. Some manufacturers used the same machines, and made different marbles in different ways over the years, in different plants. It takes a lot to learn. Look at
Joemarbles.com Home Page at the pictures there for each manufacturer. Get yourself a bunch of old marbles and get hands on experience. That's the best way by a long shot. Post them here for ID and an explanation of how they got IDed if you want. I like the challenge of IDing marbles because it hones my skills and I learn in the process. I'm not always right, but then again, nobody is when it comes to marbles.
