Very thin ring bands from around 1860s? Why so thin?

by Amy
(Fort Worth TX)

I have some very old rings passed down and I can't tell what metal. The rings are small and the bands bend very easily. The small jewels seem to be topaz and garnet with maybe paste. They don't seem to be diamonds.

Has anyone seen anything like these small rings before? Are they children's rings? Why is the metal so thin? Any info would be appreciated. My mom thinks they are from around the 1860s because of the other jewelry her great aunt had. Thank you.