Galalith is a thermoset plastic so it has to be carved rather than molded. It was made in solid colors but a lot was made with just the surface dyed so that the carving revealed another color underneath.

If you want to test them - run very hot water over a few until they are heated up. Sniff immediately for an odor. If Galalith, they will smell like wet dog or burned milk. I have heard from a number of people that they can't smell anything in any of the sniff tests so this method also depends on having a keen sense of smell.

A lot of Galalith beads I see on eBay are mislabeled as Celluloid or Bakelite. Those are the ones I can easily identify by the pictures. Most plastic beads are very difficult to ID by just the photo.