Baby jewelry is not new. Tribes of Africa, South America and the Pacific have adorned their babies and small children with shells and precious objects since time immemorial. In countries e.g. India, even male babies have traditionally worn jewelry.
Recent generations are reviving the tradition of baby jewelry though predominantly for baby girls.
Newborns are blissfully unaware of adornments, but it isn't long before they take an interest in jewelry, particularly their mother's. Some older babies wear jewelry without fuss though some seem determined to remove it. After the age of about 18 months, they come to accept and enjoy wearing a bracelet in particular, especially if it attracts attention from family and friends.
From about 2.5 years, small girls love dressing up and take a great interest in their jewelry and treasure it.
Special care should always be taken with babies wearing jewelry. Precious metals tend to be soft so care should be taken to ensure baby doesn't break her bracelet and put a piece in her mouth.
Special baby photos are enhanced by the wearing of jewelry.