Some of the necklaces come on thicker cords, the clasps are strong, and infants can easily get strangled by them. They don't work any better than placebo. Maybe buy a big chunk of amber and rub it ...

Iron Age amber beads from the Baltic Sea found in Syria. Credit: M. N. Mortensen et al. / National Museum of Denmark A recent analysis of beads discovered in the ancient city of Hama, Syria, has ...