The vast majority of garnet beads are small, because garnets large enough to make beads of this size are unusual. The color of garnets is a more purple-red. Plus, beads made from garnets typically have a high-gloss slightly metallic sheen on their surfaces. Larger garnet beads are more often dark-colored (nearly "black-looking"), and may have inclusions that are not attractive. A strand of them would not present a uniform appearance.

The consistent color, uniformity of shape and size, all suggest molded glass.

However, the Chinese did make strands of spheroidal and oblate (and less-common oval/ellipsoidal) beads from red phenolic plastics in the 1930s. These are routinely sold as 'derived from Mandarin Court necklaces,' though such an origin is very unlikely (if not impossible). I think there were similar-looking red glass beads, that might have been thought of as imitations of "cherry amber, found in Mandarin Court necklaces. Thus the confusion, or false belief.

Some strands of red phenolic plastic beads are consistent (appear uniform in size and shape), while others are somewhat more variable, and look hand-made.

It should be easy to determine if the beads in-question are molded glass or phenolic plastic (or something else).

Jamey