Amber necklaces are said to reduce teething pain and soothe babies and toddlers.  Amber contains succinic acid which is released when the  resin is warmed against the skin of the child.  Most teething necklaces are knotted in between each stone, this is for safety.  Try wrapping the necklace around the wrist or ankle as an alternative.  These are 33cm long.
 
WARNING. . . .it is important to take off the necklace when your child is sleeping as it could be a choking hazard and can pose a danger of tightening or the bead being swallowed. 
Never allow your babe to chew or suck on the necklace. It is not meant for putting in the mouth.
Please watch your little one so that any dangers are avoided.